Molecular Microbiology最新文献_第7页

DNA Packaging Specificity in the λ-Like Phages: Gifsy-1. 类λ噬菌体的 DNA 包装特异性：Gifsy-1.

IF 2.6 2区生物学

Molecular Microbiology Pub Date : 2024-10-01 Epub Date: 2024-09-05 DOI: 10.1111/mmi.15306

Michael Feiss, Jean Arens Sippy

{"title":"DNA Packaging Specificity in the λ-Like Phages: Gifsy-1.","authors":"Michael Feiss, Jean Arens Sippy","doi":"10.1111/mmi.15306","DOIUrl":"10.1111/mmi.15306","url":null,"abstract":"DNA viruses recognize viral DNA and package it into virions. Specific recognition is needed to distinguish viral DNA from host cell DNA. The λ-like Escherichia coli phages are interesting and good models to examine genome packaging by large DNA viruses. Gifsy-1 is a λ-like Salmonella phage. Gifsy-1's DNA packaging specificity was compared with those of closely related phages λ, 21, and N15. In vivo packaging studies showed that a Gifsy-1-specific phage packaged λ DNA at ca. 50% efficiency and λ packages Gifsy-1-specific DNA at ~30% efficiency. The results indicate that Gifsy-1 and λ share the same DNA packaging specificity. N15 is also shown to package Gifsy-1 DNA. Phage 21 fails to package λ, N15, and Gifsy-1-specific DNAs; the efficiencies are 0.01%, 0.01%, and 1%, respectively. A known incompatibility between the 21 helix-turn-helix motif and cosBλ is proposed to account for the inability of 21 to package Gifsy-1 DNA. A model is proposed to explain the 100-fold difference in packaging efficiency between λ and Gifsy-1-specific DNAs by phage 21. Database sequences of enteric prophages indicate that phages with Gifsy-1's DNA packaging determinants are confined to Salmonella species. Similarly, prophages with λ DNA packaging specificity are rarely found in Salmonella. It is proposed that λ and Gifsy-1 have diverged from a common ancestor phage, and that the differences may reflect adaptation of their packaging systems to host cell differences.","PeriodicalId":19006,"journal":{"name":"Molecular Microbiology","volume":" ","pages":"491-503"},"PeriodicalIF":2.6,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142133257","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Flagellar protein FliL: A many-splendored thing. 鞭毛蛋白 FliL：多种多样。

IF 2.6 2区生物学

Molecular Microbiology Pub Date : 2024-10-01 Epub Date: 2024-08-03 DOI: 10.1111/mmi.15301

Jonathan D Partridge, Rasika M Harshey

引用次数: 0

Proteolytic activity of surface-exposed HtrA determines its expression level and is needed to survive acidic conditions in Clostridioides difficile. 表面暴露的 HtrA 的蛋白水解活性决定了其表达水平，它是艰难梭菌在酸性条件下存活的必要条件。

IF 2.6 2区生物学

Molecular Microbiology Pub Date : 2024-10-01 Epub Date: 2024-07-30 DOI: 10.1111/mmi.15300

Jeroen Corver, Bart Claushuis, Tatiana M Shamorkina, Arnoud H de Ru, Merle M van Leeuwen, Paul J Hensbergen, Wiep Klaas Smits

{"title":"Proteolytic activity of surface-exposed HtrA determines its expression level and is needed to survive acidic conditions in Clostridioides difficile.","authors":"Jeroen Corver, Bart Claushuis, Tatiana M Shamorkina, Arnoud H de Ru, Merle M van Leeuwen, Paul J Hensbergen, Wiep Klaas Smits","doi":"10.1111/mmi.15300","DOIUrl":"10.1111/mmi.15300","url":null,"abstract":"To survive in the host, pathogenic bacteria need to be able to react to the unfavorable conditions that they encounter, like low pH, elevated temperatures, antimicrobial peptides and many more. These conditions may lead to unfolding of envelope proteins and this may be lethal. One of the mechanisms through which bacteria are able to survive these conditions is through the protease/foldase activity of the high temperature requirement A (HtrA) protein. The gut pathogen Clostridioides difficile encodes one HtrA homolog that is predicted to contain a membrane anchor and a single PDZ domain. The function of HtrA in C. difficile is hitherto unknown but previous work has shown that an insertional mutant of htrA displayed elevated toxin levels, less sporulation and decreased binding to target cells. Here, we show that HtrA is membrane associated and localized on the surface of C. difficile and characterize the requirements for proteolytic activity of recombinant soluble HtrA. In addition, we show that the level of HtrA in the bacteria heavily depends on its proteolytic activity. Finally, we show that proteolytic activity of HtrA is required for survival under acidic conditions.","PeriodicalId":19006,"journal":{"name":"Molecular Microbiology","volume":" ","pages":"413-428"},"PeriodicalIF":2.6,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141856031","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

TasA Fibre Interactions Are Necessary for Bacillus subtilis Biofilm Structure TasA 纤维相互作用是枯草芽孢杆菌生物膜结构的必要条件

IF 3.6 2区生物学

Molecular Microbiology Pub Date : 2024-09-30 DOI: 10.1111/mmi.15315

Natalie C. Bamford, Ryan J. Morris, Alan Prescott, Paul Murphy, Elliot Erskine, Cait E. MacPhee, Nicola R. Stanley-Wall

引用次数: 0

Peptidoglycan Endopeptidase PBP7 Facilitates the Recruitment of FtsN to the Divisome and Promotes Peptidoglycan Synthesis in Escherichia coli 肽聚糖内肽酶 PBP7 在大肠杆菌中促进 FtsN 向分裂体的招募并促进肽聚糖的合成

IF 3.6 2区生物学

Molecular Microbiology Pub Date : 2024-09-30 DOI: 10.1111/mmi.15321

Xinwei Liu, Gabriela Boelter, Waldemar Vollmer, Manuel Banzhaf, Tanneke den Blaauwen

{"title":"Peptidoglycan Endopeptidase PBP7 Facilitates the Recruitment of FtsN to the Divisome and Promotes Peptidoglycan Synthesis in Escherichia coli","authors":"Xinwei Liu, Gabriela Boelter, Waldemar Vollmer, Manuel Banzhaf, Tanneke den Blaauwen","doi":"10.1111/mmi.15321","DOIUrl":"https://doi.org/10.1111/mmi.15321","url":null,"abstract":"Escherichia coli has many periplasmic hydrolases to degrade and modify peptidoglycan (PG). However, the redundancy of eight PG endopeptidases makes it challenging to define specific roles to individual enzymes. Therefore, the cellular role of PBP7 (encoded by pbpG) is not clearly defined. In this work, we show that PBP7 localizes in the lateral cell envelope and at midcell. The C-terminal α-helix of PBP7 is crucial for midcell localization but not for its activity, which is dispensable for this localization. Additionally, midcell localization of PBP7 relies on the assembly of FtsZ up to FtsN in the divisome, and on the activity of PBP3. PBP7 was found to affect the assembly timing of FtsZ and FtsN in the divisome. The absence of PBP7 slows down the assembly of FtsN at midcell. The ΔpbpG mutant exhibited a weaker incorporation of the fluorescent D-amino acid HADA, reporting on transpeptidase activity, compared to wild-type cells. This could indicate reduced PG synthesis at the septum of the ΔpbpG strain, explaining the slower accumulation of FtsN and suggesting that endopeptidase-mediated PG cleavage may be a rate-limiting step for septal PG synthesis.","PeriodicalId":19006,"journal":{"name":"Molecular Microbiology","volume":"22 1","pages":""},"PeriodicalIF":3.6,"publicationDate":"2024-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142330267","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Unveiling the Coordinated Action of DesK/DesR and YvfT/YvfU to Control the Expression of an ABC Transporter in Bacillus subtilis 揭示 DesK/DesR 和 YvfT/YvfU 控制枯草芽孢杆菌 ABC 转运体表达的协调作用

IF 3.6 2区生物学

Molecular Microbiology Pub Date : 2024-09-30 DOI: 10.1111/mmi.15320

Pilar Fernández, Lucía Porrini, Julián Ignacio Pereyra, Daniela Albanesi, María Cecilia Mansilla

{"title":"Unveiling the Coordinated Action of DesK/DesR and YvfT/YvfU to Control the Expression of an ABC Transporter in Bacillus subtilis","authors":"Pilar Fernández, Lucía Porrini, Julián Ignacio Pereyra, Daniela Albanesi, María Cecilia Mansilla","doi":"10.1111/mmi.15320","DOIUrl":"https://doi.org/10.1111/mmi.15320","url":null,"abstract":"Two-component systems (TCSs) are vital signal transduction pathways ubiquitous among bacteria, facilitating their responses to diverse environmental stimuli. In Bacillus subtilis, the DesK histidine kinase thermosensor, together with the response regulator DesR, constitute a TCS dedicated to membrane lipid homeostasis maintenance. This TCS orchestrates the transcriptional regulation of the des gene, encoding the sole desaturase in these bacteria, Δ5-Des. Additionally, B. subtilis possesses a paralog TCS, YvfT/YvfU, with unknown target gene(s). In this work, we show that YvfT/YvfU controls the expression of the yvfRS operon that codes for an ABC transporter. Interestingly, we found that this regulation also involves the action of DesK/DesR. Notably, opposite to des, yvfRS transcription is induced at 37°C and not at 25°C. Our in vivo and in vitro experiments demonstrate that both YvfU and DesR directly bind to the operon promoter region, with DesR exerting its control over yvfRS expression in its unphosphorylated state. Our study uncovers an intriguing case of cross-regulation where two homologous TCSs interact closely to finely tune gene expression in response to environmental cues. These findings shed light on the complexity of bacterial signal transduction systems and their critical role in bacterial adaptability.","PeriodicalId":19006,"journal":{"name":"Molecular Microbiology","volume":"9 1","pages":""},"PeriodicalIF":3.6,"publicationDate":"2024-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142330268","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Analysis of bb0556 Expression and Its Role During Borrelia burgdorferi Mammalian Infection bb0556 表达及其在鲍曼不动杆菌哺乳动物感染过程中的作用分析

IF 3.6 2区生物学

Molecular Microbiology Pub Date : 2024-09-20 DOI: 10.1111/mmi.15319

Sierra George, Connor Waldron, Christina Thompson, Zhiming Ouyang

{"title":"Analysis of bb0556 Expression and Its Role During Borrelia burgdorferi Mammalian Infection","authors":"Sierra George, Connor Waldron, Christina Thompson, Zhiming Ouyang","doi":"10.1111/mmi.15319","DOIUrl":"https://doi.org/10.1111/mmi.15319","url":null,"abstract":"In Borrelia burgdorferi, BB0556 was annotated as a conserved hypothetical protein. We herein investigated gene expression and the importance of this protein during infection. Our data support that bb0556 forms an operon with five other genes. A transcriptional start site and the associated σ70-type promoter were identified in the sequences upstream of bb0554, and luciferase reporter assays indicated that this promoter is functional in B. burgdorferi. Furthermore, the sequences upstream of bb0556 contain an internal promoter to drive gene expression. bb0556 expression was affected by various environmental factors such as changes in temperature, pH, and cell density when B. burgdorferi was grown in vitro. Surprisingly, significant differences were observed for bb0556 expression between B. burgdorferi strains B31-A3 and CE162, likely due to the different cis- and trans-acting factors in these strains. Moreover, bb0556 was found to be highly expressed by B. burgdorferi in infected mice tissues, suggesting that this gene plays an important role during animal infection. To test this hypothesis, we generated a bb0556 deletion mutant in a virulent bioluminescent B. burgdorferi strain. The mutant grew normally in the medium and displayed no defect in the resistance to environmental stresses such as reactive oxygen species, reactive nitrogen species, and osmotic stress. However, when the infectivity was compared between the mutant and its parental strain using in vivo bioluminescence imaging as well as analyses of spirochete recovery and bacterial burdens in animal tissues, our data showed that, contrary to the parental strain, the mutant was unable to infect mice. Complementation of bb0556 in cis fully restored the infectious phenotype to wild-type levels. Taken together, our study demonstrates that the hypothetical protein BB0556 is a novel virulence factor essential for B. burgdorferi mammalian infection.","PeriodicalId":19006,"journal":{"name":"Molecular Microbiology","volume":"11 1","pages":""},"PeriodicalIF":3.6,"publicationDate":"2024-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142275659","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Specificity of Membrane-Associated J-Domain Protein, Caj1, in Amphotericin B Tolerance in Budding Yeast 膜相关 J-结构域蛋白 Caj1 在芽殖酵母耐受两性霉素 B 过程中的特异性

IF 3.6 2区生物学

Molecular Microbiology Pub Date : 2024-09-17 DOI: 10.1111/mmi.15318

Preeti Sagarika, Neha Dobriyal, Pakirisamy Deepsika, Avanti Vairagkar, Ankita Das, Chandan Sahi

{"title":"Specificity of Membrane-Associated J-Domain Protein, Caj1, in Amphotericin B Tolerance in Budding Yeast","authors":"Preeti Sagarika, Neha Dobriyal, Pakirisamy Deepsika, Avanti Vairagkar, Ankita Das, Chandan Sahi","doi":"10.1111/mmi.15318","DOIUrl":"https://doi.org/10.1111/mmi.15318","url":null,"abstract":"Hsp70:J-domain protein (JDP) machineries play pivotal roles in maintaining cellular proteostasis and governing various aspects of fungal physiology. While Hsp70 is known for its involvement in conferring tolerance to diverse antifungal drugs, the specific contribution of JDPs remains unclear. In this study, we examined the sensitivity of cytosolic JDP deletion strains of budding yeast to amphotericin B (AmB), a polyene antifungal agent widely utilized in fungal disease treatment due to its ability to disrupt the fungal plasma membrane (PM). Deleting Caj1, a PM-associated class II JDP, heightened susceptibility to AmB, and the protection conferred by Caj1 against AmB necessitated both its N-terminal J-domain and C-terminal lipid binding domain. Moreover, Caj1 deficiency compromised PM integrity as evidenced by increased phosphate efflux and exacerbated AmB sensitivity, particularly at elevated temperatures. Notably, phytosphingosine (PHS) addition as well as overexpression of PMP3, a positive PM integrity regulator, significantly rescued AmB sensitivity of caj1Δ cells. Our results align with the notion that Caj1 associates with the PM and cooperates with Hsp70 to regulate PM proteostasis, thereby influencing PM integrity in budding yeast. Loss of Caj1 function at the PM compromises PM protein quality control, thereby rendering yeast cells more susceptible to AmB.","PeriodicalId":19006,"journal":{"name":"Molecular Microbiology","volume":"56 1","pages":""},"PeriodicalIF":3.6,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142237016","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Small Regulatory RNAs of the Rsm Clan in Pseudomonas 假单胞菌 Rsm 家族的小调控 RNA

IF 3.6 2区生物学

Molecular Microbiology Pub Date : 2024-09-16 DOI: 10.1111/mmi.15313

María Trinidad Gallegos, Matías Garavaglia, Claudio Valverde

{"title":"Small Regulatory RNAs of the Rsm Clan in Pseudomonas","authors":"María Trinidad Gallegos, Matías Garavaglia, Claudio Valverde","doi":"10.1111/mmi.15313","DOIUrl":"https://doi.org/10.1111/mmi.15313","url":null,"abstract":"Bacteria of the genus Pseudomonas are ubiquitous on Earth due to their great metabolic versatility and adaptation to fluctuating environments and different hosts. Some groups are important animal/human and plant pathogens, whereas others are studied for their biotechnological applications, including bioremediation, biological control of phytopathogens and plant growth promotion. Notably, their adaptability is mediated by various signal transduction systems, with the post-transcriptional Gac-Rsm cascade playing a key role. This pervasive Pseudomonas pathway controls major transitions at the population level, such as motile/sessile lifestyle, primary/secondary metabolism or replicative/infective behaviour. A hallmark of the Gac-Rsm cascade is the participation of small, regulatory, non-coding RNAs of the Rsm clan. These RNAs are synthetised in response to cell-density-dependent autoinducer signals channelled through the GacS/GacA two-component system, and they counteract, by molecular mimicry, the translational control that RNA-binding proteins of the RsmA family exert over hundreds of mRNAs. Rsm RNAs have been investigated in a few Pseudomonas model species, evidencing the presence of a variable number and families of genes depending on the taxonomic clade. However, the global picture of the distribution of these riboregulators at the genus level was unknown until now. We have undertaken a comprehensive survey and annotation of the vast array of gene sequences encoding members of the Rsm RNA clan in 245 complete genomes that cover 28 phylogenomic clades across the entire genus. The properties of the different families of rsm genes, their phylogenetic radiation, as well as the features of their promoters and adjacent regions, are discussed. The novel insights presented in our manuscript will significantly boost research on the biology of these prevalent RNAs in understudied species of the genus Pseudomonas and closely related genera.","PeriodicalId":19006,"journal":{"name":"Molecular Microbiology","volume":"12 1","pages":""},"PeriodicalIF":3.6,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142234053","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Multiple Effects of L-Leucine in Escherichia coli Lead to L-Leucine-Sensitive Growth in the Absence of Unphosphorylated PtsN 大肠杆菌中 L-亮氨酸的多种效应导致在缺乏未磷酸化 PtsN 的情况下对 L-亮氨酸敏感的生长

IF 3.6 2区生物学

Molecular Microbiology Pub Date : 2024-09-14 DOI: 10.1111/mmi.15317

Neeraj Kumar, Abhijit A. Sardesai

{"title":"Multiple Effects of L-Leucine in Escherichia coli Lead to L-Leucine-Sensitive Growth in the Absence of Unphosphorylated PtsN","authors":"Neeraj Kumar, Abhijit A. Sardesai","doi":"10.1111/mmi.15317","DOIUrl":"https://doi.org/10.1111/mmi.15317","url":null,"abstract":"In E. coli K-12, the absence of unphosphorylated PtsN (unphospho-PtsN) has been proposed to cause an L-leucine-sensitive growth phenotype (LeuS) by hyperactivated K+ uptake mediated impairment of the expression of the ilvBN operon, encoding subunits of the L-valine (Val)-sensitive acetohydroxyacid synthase I (AHAS I) that renders residual AHAS activity susceptible to inhibition by Leu and K+. This leads to AHAS insufficiency and a requirement for L-isoleucine (Ile). Herein, we provide an alternate mechanism for the LeuS of the ∆ptsN mutant. Genetic and physiological studies with suppressors of the LeuS indicate that impaired expression of the ilvBN operon jointly caused by the absence of unphospho-PtsN and the presence of Leu coupled to Leu-mediated repression of expression of AHAS III leads to AHAS insufficiency rendering residual AHAS activity susceptible to chronic Val stress that may be generated by exogenous Leu. Hyperactivated K+ uptake and an elevated α-ketobutyrate level mediate elevation of ilvBN expression and alleviate the LeuS. The requirement of unphospho-PtsN as a positive regulator of ilvBN expression may buffer Ile biosynthesis against Leu-mediated AHAS insufficiency and protect AHAS I function from chronic endogenous Val generated by Leu and could be realized in certain environments that impair AHAS function.","PeriodicalId":19006,"journal":{"name":"Molecular Microbiology","volume":"46 1","pages":""},"PeriodicalIF":3.6,"publicationDate":"2024-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142231820","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0