Molecular Microbiology最新文献

The Enteric Bacterium Enterococcus faecalis Elongates and Incorporates Exogenous Short and Medium Chain Fatty Acids Into Membrane Lipids 肠道细菌粪肠球菌拉长外源短链和中链脂肪酸并将其纳入膜脂中

IF 3.6 2区生物学

Molecular Microbiology Pub Date : 2024-10-08 DOI: 10.1111/mmi.15322

Qi Zou, Huijuan Dong, John E. Cronan

{"title":"The Enteric Bacterium Enterococcus faecalis Elongates and Incorporates Exogenous Short and Medium Chain Fatty Acids Into Membrane Lipids","authors":"Qi Zou, Huijuan Dong, John E. Cronan","doi":"10.1111/mmi.15322","DOIUrl":"https://doi.org/10.1111/mmi.15322","url":null,"abstract":"Enterococcus faecalis incorporates and elongates exogeneous short- and medium-chain fatty acids to chains sufficiently long to enter membrane phospholipid synthesis. The acids are activated by the E. faecalis fatty acid kinase (FakAB) system and converted to acyl-ACP species that can enter the fatty acid synthesis cycle to become elongated. Following elongation the acyl chains are incorporated into phospholipid by the PlsY and PlsC acyltranferases. This process has little effect on de novo fatty acid synthesis in the case of short-chain acids, but a greater effect with medium-chain acids. Incorporation of exogenous short-chain fatty acids in E. faecalis was greatly increased by overexpression of either AcpA, the acyl carrier protein of fatty acid synthesis, or the phosphate acyl transferase PlsX. The PlsX of Lactococcus lactis was markedly superior to the E. faecalis PlsX in incorporation of short-chain but not long-chain acids. These manipulations also allowed unsaturated fatty acids of lengths too short for direct transfer to the phospholipid synthesis pathway to be elongated and support growth of E. faecalis unsaturated fatty acid auxotrophic strains. Short- and medium-chain fatty acids can be abundant in the human gastrointestinal tract and their elongation by E. faecalis would conserve energy and carbon by relieving the requirement for total de novo synthesis of phospholipid acyl chains.","PeriodicalId":19006,"journal":{"name":"Molecular Microbiology","volume":null,"pages":null},"PeriodicalIF":3.6,"publicationDate":"2024-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142385765","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

The dual role of a novel Sinorhizobium meliloti chemotaxis protein CheT in signal termination and adaptation. 新型瓜萎镰刀菌趋化蛋白CheT在信号终止和适应中的双重作用

IF 2.6 2区生物学

Molecular Microbiology Pub Date : 2024-10-01 Epub Date: 2024-07-30 DOI: 10.1111/mmi.15303

Alfred Agbekudzi, Timofey D Arapov, Ann M Stock, Birgit E Scharf

{"title":"The dual role of a novel Sinorhizobium meliloti chemotaxis protein CheT in signal termination and adaptation.","authors":"Alfred Agbekudzi, Timofey D Arapov, Ann M Stock, Birgit E Scharf","doi":"10.1111/mmi.15303","DOIUrl":"10.1111/mmi.15303","url":null,"abstract":"Sinorhizobium meliloti senses nutrients and compounds exuded from alfalfa host roots and coordinates an excitation, termination, and adaptation pathway during chemotaxis. We investigated the role of the novel S. meliloti chemotaxis protein CheT. While CheT and the Escherichia coli phosphatase CheZ share little sequence homology, CheT is predicted to possess an α-helix with a DXXXQ phosphatase motif. Phosphorylation assays demonstrated that CheT dephosphorylates the phosphate-sink response regulator, CheY1~P by enhancing its decay two-fold but does not affect the motor response regulator CheY2~P. Isothermal Titration Calorimetry (ITC) experiments revealed that CheT binds to a phosphomimic of CheY1~P with a KD of 2.9 μM, which is 25-fold stronger than its binding to CheY1. Dissimilar chemotaxis phenotypes of the ΔcheT mutant and cheT DXXXQ phosphatase mutants led to the hypothesis that CheT exerts additional function(s). A screen for potential binding partners of CheT revealed that it forms a complex with the methyltransferase CheR. ITC experiments confirmed CheT/CheR binding with a KD of 19 μM, and a SEC-MALS analysis determined a 1:1 and 2:1 CheT/CheR complex formation. Although they did not affect each other's enzymatic activity, CheT binding to CheY1~P and CheR may serve as a link between signal termination and sensory adaptation.","PeriodicalId":19006,"journal":{"name":"Molecular Microbiology","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141856032","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

Cytosolic Factors Controlling PASTA Kinase-Dependent ReoM Phosphorylation. 控制 PASTA 激酶依赖性 ReoM 磷酸化的细胞膜因素

IF 2.6 2区生物学

Molecular Microbiology Pub Date : 2024-10-01 Epub Date: 2024-09-08 DOI: 10.1111/mmi.15307

Patricia Rothe, Sabrina Wamp, Lisa Rosemeyer, Jeanine Rismondo, Joerg Doellinger, Angelika Gründling, Sven Halbedel

{"title":"Cytosolic Factors Controlling PASTA Kinase-Dependent ReoM Phosphorylation.","authors":"Patricia Rothe, Sabrina Wamp, Lisa Rosemeyer, Jeanine Rismondo, Joerg Doellinger, Angelika Gründling, Sven Halbedel","doi":"10.1111/mmi.15307","DOIUrl":"10.1111/mmi.15307","url":null,"abstract":"Bacteria adapt the biosynthesis of their envelopes to specific growth conditions and prevailing stress factors. Peptidoglycan (PG) is the major component of the cell wall in Gram-positive bacteria, where PASTA kinases play a central role in PG biosynthesis regulation. Despite their importance for growth, cell division and antibiotic resistance, the mechanisms of PASTA kinase activation are not fully understood. ReoM, a recently discovered cytosolic phosphoprotein, is one of the main substrates of the PASTA kinase PrkA in the Gram-positive human pathogen Listeria monocytogenes. Depending on its phosphorylation, ReoM controls proteolytic stability of MurA, the first enzyme in the PG biosynthesis pathway. The late cell division protein GpsB has been implicated in PASTA kinase signalling. Consistently, we show that L. monocytogenes prkA and gpsB mutants phenocopied each other. Analysis of in vivo ReoM phosphorylation confirmed GpsB as an activator of PrkA leading to the description of structural features in GpsB that are important for kinase activation. We further show that ReoM phosphorylation is growth phase-dependent and that this kinetic is reliant on the protein phosphatase PrpC. ReoM phosphorylation was inhibited in mutants with defects in MurA degradation, leading to the discovery that MurA overexpression prevented ReoM phosphorylation. Overexpressed MurA must be able to bind its substrates and interact with ReoM to exert this effect, but the extracellular PASTA domains of PrkA or MurJ flippases were not required. Our results indicate that intracellular signals control ReoM phosphorylation and extend current models describing the mechanisms of PASTA kinase activation.","PeriodicalId":19006,"journal":{"name":"Molecular Microbiology","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142154613","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

Differential CheR Affinity for Chemoreceptor C-Terminal Pentapeptides Modulates Chemotactic Responses. 化学感受器 C 端五肽的不同亲和力调节趋化反应

IF 2.6 2区生物学

Molecular Microbiology Pub Date : 2024-10-01 Epub Date: 2024-08-23 DOI: 10.1111/mmi.15305

Félix Velando, Elizabet Monteagudo-Cascales, Miguel A Matilla, Tino Krell

{"title":"Differential CheR Affinity for Chemoreceptor C-Terminal Pentapeptides Modulates Chemotactic Responses.","authors":"Félix Velando, Elizabet Monteagudo-Cascales, Miguel A Matilla, Tino Krell","doi":"10.1111/mmi.15305","DOIUrl":"10.1111/mmi.15305","url":null,"abstract":"Many chemoreceptors contain a C-terminal pentapeptide at the end of a linker. In Escherichia coli, this pentapeptide forms a high-affinity binding site for CheR and phosphorylated CheB, and its removal interferes with chemoreceptor adaptation. Analysis of chemoreceptors revealed significant variation in their pentapeptide sequences, and bacteria often possess multiple chemoreceptors with differing pentapeptides. To assess whether this sequence variation alters CheR affinity and chemotaxis, we used Pectobacterium atrosepticum SCRI1043 as a model. SCRI1043 has 36 chemoreceptors, with 19 of them containing a C-terminal pentapeptide. We show that the affinity of CheR for the different pentapeptides varies up to 11-fold (KD 90 nM to 1 μM). Pentapeptides with the highest and lowest affinities differ only in a single amino acid. Deletion of the cheR gene abolishes chemotaxis. The replacement of the pentapeptide in the PacC chemoreceptor with those of the highest and lowest affinities significantly reduced chemotaxis to its cognate chemoeffector, L-Asp. Altering the PacC pentapeptide also reduced chemotaxis to L-Ser, but not to nitrate, which are responses mediated by the nontethered PacB and PacN chemoreceptors, respectively. Changes in the pentapeptide sequence thus modulate the response of the cognate receptor and that of another chemoreceptor.","PeriodicalId":19006,"journal":{"name":"Molecular Microbiology","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142046919","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

Tag Recycling in the Pup-Proteasome System is Essential for Mycobacterium smegmatis Survival Under Starvation Conditions. 幼虫-蛋白酶体系统中的标签循环对饥饿条件下的分枝杆菌生存至关重要

IF 2.6 2区生物学

Molecular Microbiology Pub Date : 2024-10-01 Epub Date: 2024-09-05 DOI: 10.1111/mmi.15312

Erez Zerbib, Roni Levin, Eyal Gur

引用次数: 0

Bright New Resources for Syphilis Research: Genetically Encoded Fluorescent Tags for Treponema pallidum and Sf1Ep Cells. 梅毒研究的崭新资源：用于苍白螺旋体和 Sf1Ep 细胞的基因编码荧光标签

IF 2.6 2区生物学

Molecular Microbiology Pub Date : 2024-10-01 Epub Date: 2024-08-08 DOI: 10.1111/mmi.15304

Linda Grillová, Emily Romeis, Nicole A P Lieberman, Lauren C Tantalo, Linda H Xu, Barbara Molini, Aldo T Trejos, George Lacey, David Goulding, Nicholas R Thomson, Alexander L Greninger, Lorenzo Giacani

{"title":"Bright New Resources for Syphilis Research: Genetically Encoded Fluorescent Tags for Treponema pallidum and Sf1Ep Cells.","authors":"Linda Grillová, Emily Romeis, Nicole A P Lieberman, Lauren C Tantalo, Linda H Xu, Barbara Molini, Aldo T Trejos, George Lacey, David Goulding, Nicholas R Thomson, Alexander L Greninger, Lorenzo Giacani","doi":"10.1111/mmi.15304","DOIUrl":"10.1111/mmi.15304","url":null,"abstract":"The recently discovered methodologies to cultivate and genetically manipulate Treponema pallidum subsp. pallidum (T. pallidum) have significantly helped syphilis research, allowing the in vitro evaluation of antibiotic efficacy, performance of controlled studies to assess differential treponemal gene expression, and generation of loss-of-function mutants to evaluate the contribution of specific genetic loci to T. pallidum virulence. Building on this progress, we engineered the T. pallidum SS14 strain to express a red-shifted green fluorescent protein (GFP) and Sf1Ep cells to express mCherry and blue fluorescent protein (BFP) for enhanced visualization. These new resources improve microscopy- and cell sorting-based applications for T. pallidum, better capturing the physical interaction between the host and pathogen, among other possibilities. Continued efforts to develop and share new tools and resources are required to help our overall knowledge of T. pallidum biology and syphilis pathogenesis reach that of other bacterial pathogens, including spirochetes.","PeriodicalId":19006,"journal":{"name":"Molecular Microbiology","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11479824/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141902420","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

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":null,"pages":null},"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

Atypical Mycobacterium abscessus BlaRI Ortholog Mediates Regulation of Energy Metabolism but Not β-Lactam Resistance. 非典型脓肿分枝杆菌 BlaRI 同源物介导能量代谢调节而非β-内酰胺抗性。

IF 2.6 2区生物学

Molecular Microbiology Pub Date : 2024-10-01 Epub Date: 2024-09-22 DOI: 10.1111/mmi.15314

Lauren E Bonefont, Haley C Davenport, Catherine T Chaton, Konstantin V Korotkov, Kyle H Rohde

{"title":"Atypical Mycobacterium abscessus BlaRI Ortholog Mediates Regulation of Energy Metabolism but Not β-Lactam Resistance.","authors":"Lauren E Bonefont, Haley C Davenport, Catherine T Chaton, Konstantin V Korotkov, Kyle H Rohde","doi":"10.1111/mmi.15314","DOIUrl":"10.1111/mmi.15314","url":null,"abstract":"Mycobacterium abscessus (Mab) is highly drug resistant, and understanding regulation of antibiotic resistance is critical to future antibiotic development. Regulatory mechanisms controlling Mab's β-lactamase (BlaMab) that mediates β-lactam resistance remain unknown. S. aureus encodes a prototypical protease-mediated two-component system BlaRI regulating the β-lactamase BlaZ. BlaR binds extracellular β-lactams, activating an intracellular peptidase domain which cleaves BlaI to derepress blaZ. Mycobacterium tuberculosis (Mtb) encodes homologs of BlaRI (which we will denote as BlaIR to reflect the inverted gene order in mycobacteria) that regulate not only the Mtb β-lactamase, blaC, but also additional genes related to respiration. We identified orthologs of blaIRMtb in Mab and hypothesized that they regulate blaMab. Surprisingly, neither deletion of blaIRMab nor overexpression of only blaIMab altered blaMab expression or β-lactam susceptibility. However, BlaIMab did bind to conserved motifs upstream of several Mab genes involved in respiration, yielding a putative regulon that partially overlapped with BlaIMtb. Prompted by evidence that respiration inhibitors including clofazimine induce the BlaI regulon in Mtb, we found that clofazimine triggers induction of blaIRMab and its downstream regulon. Highlighting an important role for BlaIRMab in adapting to disruptions in energy metabolism, constitutive repression of the BlaIMab regulon rendered Mab highly susceptible to clofazimine. In addition to our unexpected findings that BlaIRMab does not regulate β-lactam resistance, this study highlights the novel role of mycobacterial BlaRI-type regulators in regulating electron transport and respiration.","PeriodicalId":19006,"journal":{"name":"Molecular Microbiology","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142291742","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":null,"pages":null},"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