Journal of Bacteriology最新文献

{"title":"The histidine kinase NahK regulates denitrification and nitric oxide accumulation through RsmA in <i>Pseudomonas aeruginosa</i>.","authors":"Danielle Guercio, Elizabeth Boon","doi":"10.1128/jb.00408-24","DOIUrl":"10.1128/jb.00408-24","url":null,"abstract":"<p><p><i>Pseudomonas aeruginosa</i> have a versatile metabolism; they can adapt to many stressors, including limited oxygen and nutrient availability. This versatility is especially important within a biofilm where multiple microenvironments are present. As a facultative anaerobe, <i>P. aeruginosa</i> can survive under anaerobic conditions utilizing denitrification. This process produces nitric oxide (NO) which has been shown to result in cell elongation. However, the molecular mechanism underlying this phenotype is poorly understood. Our laboratory has previously shown that NosP is a NO-sensitive hemoprotein that works with the histidine kinase NahK to regulate biofilm formation in <i>P. aeruginosa</i>. In this study, we identify NahK as a novel regulator of denitrification under anaerobic conditions. Under anaerobic conditions, deletion of <i>nahK</i> leads to a reduction of growth coupled with reduced transcriptional expression and activity of the denitrification reductases. Furthermore, during stationary phase under anaerobic conditions, Δ<i>nahK</i> does not exhibit cell elongation, which is characteristic of <i>P. aeruginosa</i>. We determine the loss of cell elongation is due to changes in NO accumulation in Δ<i>nahK</i>. We further provide evidence that NahK may regulate denitrification through modification of RsmA levels.</p><p><strong>Importance: </strong><i>Pseudomonas aeruginosa</i> is an opportunistic multi-drug resistance pathogen that is associated with hospital-acquired infections. <i>P. aeruginosa</i> is highly virulent, in part due to its versatile metabolism and ability to form biofilms. Therefore, better understanding of the molecular mechanisms that regulate these processes should lead to new therapeutics to treat <i>P. aeruginosa</i> infections. The histidine kinase NahK has been previously shown to be involved in both nitric oxide (NO) signaling and quorum sensing through RsmA. The data presented here demonstrate that NahK is responsive to NO produced during denitrification to regulate cell morphology. Understanding the role of NahK in metabolism under anaerobic conditions has larger implications in determining its role in a heterogeneous metabolic environment such as a biofilm.</p>","PeriodicalId":15107,"journal":{"name":"Journal of Bacteriology","volume":" ","pages":"e0040824"},"PeriodicalIF":2.7,"publicationDate":"2025-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11784011/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142807075","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"RhlR-mediated cooperation in cystic fibrosis-adapted isolates of <i>Pseudomonas aeruginosa</i>.","authors":"Renae L Cruz, Tiia S Freeman, Kyle L Asfahl, Nicole E Smalley, Ajai A Dandekar","doi":"10.1128/jb.00344-24","DOIUrl":"10.1128/jb.00344-24","url":null,"abstract":"<p><p><i>Pseudomonas aeruginosa</i> uses quorum sensing (QS) to regulate the expression of dozens of genes, many of which encode shared products, called \"public goods.\" <i>P. aeruginosa</i> possesses two complete acyl-homoserine lactone (AHL) QS circuits: the LasR-I and RhlR-I systems. Canonically, these systems are hierarchically organized: RhlR-I activity depends on LasR-I activation. However, in contrast to laboratory strains, isolates from people with cystic fibrosis can engage in AHL QS using only the transcription factor RhlR. In these isolates, RhlR regulates AHL QS and the production of secreted public goods, such as the exoprotease elastase, which are accessible to both producing and non-producing cells. When <i>P. aeruginosa</i> strains that use LasR to regulate elastase production are grown on casein as the sole carbon and energy source, LasR-null mutant \"cheaters\" commonly arise in populations due to a selective growth advantage. We asked if these social dynamics might differ in \"RhlR cooperators\": populations that use RhlR, not LasR, to regulate public goods. We passaged RhlR cooperators from several genetic backgrounds in casein broth. We found that cheaters emerged among most RhlR cooperators. However, in one isolate background, E90, RhlR-null mutants were dramatically outcompeted by RhlR cooperators. In this background, the mechanism by which RhlR mutants are outcompeted by RhlR cooperators is AHL-dependent and occurs in stationary phase but is not the same as previously described \"policing\" mechanisms. Our data suggest that cheating, or the lack thereof, does not explain the lack of RhlR mutants observed in most infection environments.IMPORTANCEQuorum sensing (QS) mutants arise in a variety of populations of bacteria, but mutants of the gene encoding the transcription factor RhlR in <i>Pseudomonas aeruginosa</i> appear to be infrequent. Our work provides insight on the mechanisms through which RhlR-mediated cooperation is maintained in a LasR-null population of <i>P. aeruginosa</i>. Characterizing the selective pressure(s) that disfavor mutations from occurring in RhlR may enhance our understanding of <i>P. aeruginosa</i> evolution in chronic infections and potentially guide the development of therapeutics targeting the RhlR-I QS circuit.</p>","PeriodicalId":15107,"journal":{"name":"Journal of Bacteriology","volume":" ","pages":"e0034424"},"PeriodicalIF":2.7,"publicationDate":"2025-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11784195/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142818016","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Erratum for Soto-Aceves et al., \"The relationship between <i>pqs</i> gene expression and acylhomoserine lactone signaling in <i>Pseudomonas aeruginosa</i>\".","authors":"Martín P Soto-Aceves, Nicole E Smalley, Amy L Schaefer, E Peter Greenberg","doi":"10.1128/jb.00475-24","DOIUrl":"10.1128/jb.00475-24","url":null,"abstract":"","PeriodicalId":15107,"journal":{"name":"Journal of Bacteriology","volume":" ","pages":"e0047524"},"PeriodicalIF":2.7,"publicationDate":"2025-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11784434/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142807094","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"2-Thiouridine formation in <i>Escherichia coli</i>: a critical review.","authors":"Silke Leimkühler","doi":"10.1128/jb.00420-24","DOIUrl":"10.1128/jb.00420-24","url":null,"abstract":"<p><p>Modifications of transfer RNA (tRNA) have been shown to play critical roles in the biogenesis, metabolism, structural stability, and function of RNA molecules, and the specific modifications of nucleobases with sulfur atoms in tRNA are present in prokaryotes and eukaryotes. The s² group of s²U34 stabilizes anticodon structure, confers ribosome-binding ability to tRNA, and improves reading frame maintenance. In particular, specific enzymes catalyze the biosynthesis of sulfur-containing nucleosides of s²U34, such as the L-cysteine desulfurase IscS and the tRNA thiouridylase MnmA in <i>Escherichia coli</i>. Until recently, the mechanism of sulfur transfer in <i>E. coli</i> was considered to involve persulfide chemistry; however, a newly proposed mechanism suggests the involvement of a [4Fe-4S] cluster bound to MnmA. This review provides a critical appraisal of recent evidence for [4Fe-4S]-dependent or [4Fe-4S]-independent tRNA thiolation in 2-thiouridine formation.</p>","PeriodicalId":15107,"journal":{"name":"Journal of Bacteriology","volume":" ","pages":"e0042024"},"PeriodicalIF":2.7,"publicationDate":"2025-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11784392/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142807050","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A new target of multiple lysine methylation in bacteria.","authors":"Shori Inoue, Shogo Yoshimoto, Katsutoshi Hori","doi":"10.1128/jb.00325-24","DOIUrl":"10.1128/jb.00325-24","url":null,"abstract":"<p><p>The methylation of ε-amino groups in protein lysine residues is an important posttranslational modification in eukaryotes. This modification plays a pivotal role in the regulation of diverse biological processes, including epigenetics, transcriptional control, and cellular signaling. Recent research has begun to reveal the potential role of methylation in modulating bacterial immune evasion and adherence to host cells. In this study, we analyzed the cell surface proteins of the toluene-degrading bacterium <i>Acinetobacter</i> sp. Tol 5 by label-free liquid chromatography‒mass spectrometry and found multiple lysine methylation in its trimeric autotransporter adhesin (TAA), AtaA. Over 130 lysine residues of AtaA, consisting of 3,630 amino acids and containing 234 lysine residues, were methylated. We identified that the outer membrane protein lysine methyltransferase (OM PKMT) of Tol 5, KmtA, specifically methylates the lysine residues of AtaA. In the KmtA-deficient mutant, most lysine methylations on AtaA were absent, indicating that KmtA is responsible for the methylation of multiple lysine residues throughout AtaA. Bioinformatic analysis revealed that the OM PKMT genes were widely distributed among Gram-negative bacteria, including pathogens with TAAs that promote infectivity, such as <i>Burkholderia mallei</i> and <i>Haemophilus influenzae</i>. Although KmtA has sequence similarities to the OM PKMTs of <i>Rickettsia</i> involved in infectivity, KmtA-like PKMTs formed a distinct cluster from those of the <i>Rickettsia</i> type according to the clustering analysis, suggesting that they are new types of OM PKMTs. Furthermore, the deletion of Tol 5 KmtA led to an increase in AtaA on the cell surface and enhanced bacterial adhesion, resulting in slower growth.</p><p><strong>Importance: </strong>Lysine methylation has been underexplored in prokaryotes, and information on it is limited to some pathogens. Our finding is the second case of multiple lysine methylation of bacterial outer membrane (OM) proteins, following that of OmpB of <i>Rickettsia</i>. The newly found target of methylation, AtaA, a trimeric autotransporter adhesin family protein of <i>Acinetobacter</i> sp. Tol 5 isolated from activated sludge, extends our understanding of OM protein methylation to non-pathogenic environmental strains. The newly identified enzyme KmtA shows higher specificity than rickettsial lysin methylases, protein lysine methyltransferases, and methylates more lysine residues of the target, which raises interest in the mechanism underlying its biological specificity. The widespread presence of KmtA-like PKMTs throughout Gram-negative bacteria suggests that lysine methylation functions more extensively in bacterial physiology than previously recognized.</p>","PeriodicalId":15107,"journal":{"name":"Journal of Bacteriology","volume":" ","pages":"e0032524"},"PeriodicalIF":2.7,"publicationDate":"2025-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11784438/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142807054","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The <i>Chlamydia pneumoniae</i> inclusion membrane protein Cpn0308 interacts with host protein ACBD3.","authors":"Liang Ma, Xiao-Hui Jia, Zhe Gao, Yan Zhou, Yong-Ting Cheng, Ping Li, Tian-Jun Jia","doi":"10.1128/jb.00275-24","DOIUrl":"10.1128/jb.00275-24","url":null,"abstract":"<p><p><i>Chlamydia pneumoniae</i> is an obligate intracellular bacterium of eukaryotic cells characterized by a unique biphasic life cycle; its biosynthesis and replication must occur within a cytoplasmic vacuole or inclusion. Certain inclusion membrane proteins have been demonstrated to mediate the interactions between intra-inclusion chlamydial organisms and the host cell. It has been demonstrated previously that the <i>C. pneumoniae</i>-encoded Cpn0308 localizes to the inclusion membrane; however, its function remains unknown. In the current study, a yeast two-hybrid assay was conducted to screen Cpn0308 as a bait against a HeLa cell cDNA library, revealing its binding to the host protein acyl-coenzyme A binding domain-containing 3 (ACBD3). The interaction between Cpn0308 and ACBD3 was confirmed through co-immunoprecipitation and GST (Glutathione S-transferase) pull-down assays. The two proteins were also co-localized in HeLa cells co-expressing Cpn0308 and ACBD3, as well as in <i>C. pneumoniae</i>-infected cells, as observed under confocal fluorescence microscopy. Given that ACBD3 plays a crucial role in maintaining host cell lipid homeostasis and its Golgi dynamic domain is responsible for interacting with Cpn0308, we hypothesize that the Cpn0308-ACBD3 interaction may facilitate <i>C. pneumoniae</i>'s acquisition of host lipids, thereby benefiting chlamydial survival. This study lays a foundation for further elucidating the mechanisms of Cpn0308-mediated <i>C. pneumoniae</i> pathogenesis.IMPORTANCEThe biosynthesis and replication of <i>Chlamydia pneumoniae</i> (<i>Cpn</i>) must occur within the cytoplasmic vacuoles or inclusions of host cells. Inclusion bodies play a crucial role in mediating the interactions between <i>Cpn</i> and host cells. Cpn0308 is localized to the inclusion membrane; however, its function is unknown. In this study, Cpn0308 was found to bind to host protein acyl-coenzyme A binding domain-containing 3 (ACBD3) through some standard approaches. Co-localization of the two proteins was observed in both original HeLa cells and Cpn-infected HeLa cells. ACBD3 plays a significant role in maintaining lipid homeostasis in host cells; we speculate that the Cpn0308-ACBD3 interaction may facilitate the acquisition of host lipids by <i>C. pneumoniae</i>, thereby enhancing chlamydial survival.</p>","PeriodicalId":15107,"journal":{"name":"Journal of Bacteriology","volume":" ","pages":"e0027524"},"PeriodicalIF":2.7,"publicationDate":"2025-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11784219/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142894593","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Outer membrane lipoproteins: late to the party, but the center of attention.","authors":"Kerrie L May, Marcin Grabowicz","doi":"10.1128/jb.00442-24","DOIUrl":"10.1128/jb.00442-24","url":null,"abstract":"<p><p>An outer membrane (OM) is the hallmark feature that is often used to distinguish \"Gram-negative\" bacteria. Our understanding of how the OM is built rests largely on studies of <i>Escherichia coli</i>. In that organism-and seemingly in all species of the Proteobacterial phyla-the essential pathways that assemble the OM each rely on one or more lipoproteins that have been trafficked to the OM. Hence, the lipoprotein trafficking pathway appeared to be foundational for the ability of these bacteria to build their OM. However, such a notion now appears to be misguided. New phylogenetic analyses now show us that lipoprotein trafficking was likely the very last of the essential OM assembly systems to have evolved. The emergence of lipoprotein trafficking must have been a powerful innovation for the ancestors of Proteobacteria, given how it assumed such a central place in OM biogenesis. In this minireview, we broadly discuss the biosynthesis and trafficking of lipoproteins and ponder why the newest OM assembly system (lipoprotein trafficking) has become so key to building the Proteobacterial OM. We examine the diversity among lipoprotein trafficking systems, noting uniting commonalities and highlighting key differences. Current novel antibiotic development is targeted against a small subset of Proteobacterial species that cause severe human diseases; several inhibitors of lipoprotein biosynthesis and OM trafficking have been recently reported that may become new antibiotics. Understanding the diversity in lipoprotein trafficking may yield selective new antibiotics that preferentially kill important human pathogens while sparing species of normal healthy flora.</p>","PeriodicalId":15107,"journal":{"name":"Journal of Bacteriology","volume":" ","pages":"e0044224"},"PeriodicalIF":2.7,"publicationDate":"2025-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11784454/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142818014","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Exploring aggregation genes in a <i>P. aeruginosa</i> chronic infection model.","authors":"Alexa D Gannon, Jenet Matlack, Sophie E Darch","doi":"10.1128/jb.00429-24","DOIUrl":"10.1128/jb.00429-24","url":null,"abstract":"<p><p>Bacterial aggregates are observed in both natural and artificial environments. In the context of disease, aggregates have been isolated from chronic and acute infections. <i>Pseudomonas aeruginosa</i> (<i>Pa</i>) aggregates contribute significantly to chronic infections, particularly in the lungs of people with cystic fibrosis (CF). Unlike the large biofilm structures observed <i>in vitro</i>, <i>Pa</i> in CF sputum forms smaller aggregates (~10-1,000 cells), and the mechanisms behind their formation remain underexplored. This study aims to identify genes essential and unique <i>to</i> Pa aggregate formation in a synthetic CF sputum media (SCFM2). We cultured <i>Pa</i> strain PAO1 in SCFM2 and LB, both with and without mucin, and used RNA sequencing (RNA-seq) to identify differentially expressed genes. The presence of mucin revealed 13 significantly differentially expressed (DE) genes, predominantly downregulated, with 40% encoding hypothetical proteins unique to aggregates. Using high-resolution microscopy, we assessed the ability of mutants to form aggregates. Notably, no mutant exhibited a completely planktonic phenotype. Instead, we identified multiple spatial phenotypes described as \"normal,\" \"entropic,\" or \"impaired.\" Entropic mutants displayed tightly packed, raft-like structures, while impaired mutants had loosely packed cells. Predictive modeling linked the prioritized genes to metabolic shifts, iron acquisition, surface modification, and quorum sensing. Co-culture experiments with wild-type PAO1 revealed further spatial heterogeneity and the ability to \"rescue\" some mutant phenotypes, suggesting cooperative interactions during growth. This study enhances our understanding of <i>Pa</i> aggregate biology, specifically the genes and pathways unique to aggregation in CF-like environments. Importantly, it provides insights for developing therapeutic strategies targeting aggregate-specific pathways.</p><p><strong>Importance: </strong>This study identifies genes essential for the formation of <i>Pseudomonas aeruginosa</i> (Pa) aggregates in cystic fibrosis (CF) sputum, filling a critical gap in understanding their specific biology. Using a synthetic CF sputum model (SCFM2) and RNA sequencing, 13 key genes were identified, whose disruption led to distinct spatial phenotypes observed through high-resolution microscopy. The addition of wild-type cells either rescued the mutant phenotype or increased spatial heterogeneity, suggesting cooperative interactions are involved in aggregate formation. This research advances our knowledge of <i>Pa</i> aggregate biology, particularly the unique genes and pathways involved in CF-like environments, offering valuable insights for developing targeted therapeutic strategies against aggregate-specific pathways.</p>","PeriodicalId":15107,"journal":{"name":"Journal of Bacteriology","volume":" ","pages":"e0042924"},"PeriodicalIF":2.7,"publicationDate":"2025-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11784459/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142807023","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An unusual activity of mycobacterial MutT1 Nudix hydrolase domain as a protein phosphatase regulates nucleoside diphosphate kinase function.","authors":"Elhassan Ali Fathi Emam, Koyel Roy, Devendra Pratap Singh, Deepak K Saini, Umesh Varshney","doi":"10.1128/jb.00314-24","DOIUrl":"10.1128/jb.00314-24","url":null,"abstract":"<p><p>MutT proteins are Nudix hydrolases characterized by the presence of a Nudix box, GX5EX7REUXEEXGU, where U is a bulky hydrophobic residue and X is any residue. Major MutT proteins hydrolyze 8-oxo-(d)GTP (8-oxo-GTP or 8-oxo-dGTP) to the corresponding 8-oxo-(d)GMP, preventing their incorporation into nucleic acids. Mycobacterial MutT1 comprises an N-terminal domain (NTD) harboring the Nudix box motif, and a C-terminal domain (CTD) harboring the RHG histidine phosphatase motif. Interestingly, unlike other MutTs, the MutT1 hydrolyses the mutagenic 8-oxo-(d)GTP to the corresponding 8-oxo-(d)GDP. Nucleoside diphosphate kinase (NDK), a conserved protein, carries out reversible conversion of (d)NDPs to (d)NTPs through phospho-NDK (NDK-<i>Pi</i>) intermediate. Recently, we showed that NDK-<i>Pi</i> converts 8-oxo-dGDP to 8-oxo-dGTP and escalates A to C mutations in a MutT-deficient <i>Escherichia coli</i>. We now show that both <i>Mycobacterium tuberculosis</i> MutT1 and <i>Mycobacterium smegmatis</i> MutT1, through their NTD (Nudix hydrolase motifs) function as protein phosphatase to regulate the levels of NDK-<i>Pi</i> and prevent it from catalyzing conversion of (d)NDPs to (d)NTPs (including conversion of 8-oxo-dGDP to 8-oxo-dGTP). To corroborate this function, we show that <i>Msm</i>MutT1 decreases A to C mutations in <i>E. coli</i> under the conditions of <i>Eco</i>NDK overexpression.IMPORTANCEMutT proteins, having a Nudix box domain, hydrolyze the mutagenic 8-oxo-dGTP to 8-oxo-dGMP. However, mycobacterial MutT (MutT1) comprises an N-terminal domain (NTD) harboring a Nudix box, and a C-terminal domain (CTD) harboring an RHG histidine phosphatase. Unlike other MutTs, mycobacterial MutT1 hydrolyses 8-oxo-dGTP to 8-oxo-dGDP. Nucleoside diphosphate kinase (NDK), a conserved protein, converts 8-oxo-dGDP to 8-oxo-dGTP through phospho-NDK (NDK-<i>Pi</i>) intermediate and escalates A to C mutations. Here, we show that the mycobacterial MutT1 is unprecedented in that its NTD (Nudix box), functions as protein phosphatase to regulate NDK-<i>Pi</i> levels and prevents it from converting dNDPs to dNTPs (including 8-oxo-dGDP to 8-oxo-dGTP conversion). In addition, mycobacterial MutT1 decreases A to C mutations in <i>Escherichia coli</i> under the conditions of NDK overexpression.</p>","PeriodicalId":15107,"journal":{"name":"Journal of Bacteriology","volume":" ","pages":"e0031424"},"PeriodicalIF":2.7,"publicationDate":"2025-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11784022/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142807069","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Absence of biofilm adhesin proteins changes surface attachment and cell strategy for <i>Desulfovibrio vulgaris</i> Hildenborough.","authors":"C Pete Pickens, Dongyu Wang, Chongle Pan, Kara B De León","doi":"10.1128/jb.00379-24","DOIUrl":"10.1128/jb.00379-24","url":null,"abstract":"<p><p>Ubiquitous in nature, biofilms provide stability in a fluctuating environment and provide protection from stressors. Biofilms formed in industrial processes are exceedingly problematic and costly. While biofilms of sulfate-reducing bacteria in the environment are often beneficial because of their capacity to remove toxic metals from water, in industrial pipelines, these biofilms cause a major economic impact due to their involvement in metal and concrete corrosion. The mechanisms by which biofilms of sulfate-reducing bacteria form, however, are not well understood. Our previous work identified two proteins, named by their gene loci DVU1012 and DVU1545, as adhesins in the model sulfate-reducing bacterium, <i>Desulfovibrio vulgaris</i> Hildenborough. Both proteins are localized to the cell surface and the presence of at least one of the proteins, with either being sufficient, is necessary for biofilm formation to occur. In this study, differences in cell attachment and early biofilm formation in single deletion mutants of these adhesins were identified. Cells lacking DVU1012 had a different attachment strategy from wild-type (WT) and ΔDVU1545 cells, more often attaching as single cells than aggregates, which indicated that DVU1012 was more important for cell-to-cell attachment. ΔDVU1545 cells had increased cell attachment compared to WT cells when grown in static cultures. To date, comparisons of the <i>D. vulgaris</i> Hildenborough have been made to the large adhesion protein system in environmental pseudomonads. Yet, we and others have shown distinct mechanistic differences in the systems. We propose to name these proteins in <i>D. vulgaris</i> Hildenborough biofilm formation system to facilitate comparisons.</p><p><strong>Importance: </strong>Biofilms of sulfate-reducing bacteria contribute to biocorrosion, costing the United States hundreds of millions of dollars annually. In contrast, these biofilms can be used to bioremediate toxic heavy metals and to generate bioelectricity. As one of the most abundant groups of organisms on Earth, it is pertinent to better understand mechanistically how the biofilms of sulfate-reducing bacteria form so we may use this knowledge to help in efforts to mitigate biocorrosion, to promote bioremediation, and to produce clean energy. This study shows that the absence of either one of two biofilm adhesins impacts surface colonization by a sulfate-reducing bacterium, and that these two biofilm adhesins differ in their effect on cell attachment compared to other well-documented bacteria such as <i>Pseudomonas</i> species.</p>","PeriodicalId":15107,"journal":{"name":"Journal of Bacteriology","volume":" ","pages":"e0037924"},"PeriodicalIF":2.7,"publicationDate":"2025-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11784015/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142915168","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}