FEMS microbes最新文献_第5页

Crystal structure of methanogen MtxX (Methanogen Marker Protein MMP4) from Methanothermobacter thermautotrophicus ΔH. 产热自养甲烷杆菌产甲烷菌MtxX （methanogen Marker Protein MMP4）的晶体结构ΔH。

IF 4.2

FEMS microbes Pub Date : 2026-02-20 eCollection Date: 2026-01-01 DOI: 10.1093/femsmc/xtag011

Andrew J Sutherland-Smith, Vincenzo Carbone, Wiebke Kaziur-Cegla, Marion Woermann, Linley R Schofield, Ron S Ronimus

{"title":"Crystal structure of methanogen MtxX (Methanogen Marker Protein MMP4) from Methanothermobacter thermautotrophicus ΔH.","authors":"Andrew J Sutherland-Smith, Vincenzo Carbone, Wiebke Kaziur-Cegla, Marion Woermann, Linley R Schofield, Ron S Ronimus","doi":"10.1093/femsmc/xtag011","DOIUrl":"10.1093/femsmc/xtag011","url":null,"abstract":"MtxX, also known as Methanogen Marker Protein 4 (MMP4), is a member of the group of proteins conserved in archaeal methanogens called the Methanogen Marker Proteins (MMPs). Owing to this taxonomic distribution the MMPs are presumed to have roles related to methanogenesis or are evidence for an evolutionary history associated with methanogenic processes. MtxX is sequence-annotated as either a methyltransferase (EC 2.1.1.-) or a phosphate acetyl/butyryltransferase (EC 2.3.1.8/2.3.1.19). Gene synteny analysis shows mtxX is located next to other MMP genes in Methanomicrobiales, Methanotrichales, and Methanocaldococcus genomes, while in Methanobacteria and Methanococci it is positioned adjacent to undecaprenyl pyrophosphate synthase, a cell wall biosynthesis enzyme. We describe the crystal structure for MtxX from Methanothermobacter thermautotrophicus ΔH showing that it has a protein fold homologous to phosphate acetyltransferases and decarboxylating NAD(P)-dependent dehydrogenases. The MtxX structure has a conserved binding cleft which is the presumptive functional site based on crystallographic symmetry-related molecular binding interactions and structural homology.","PeriodicalId":73024,"journal":{"name":"FEMS microbes","volume":"7 ","pages":"xtag011"},"PeriodicalIF":4.2,"publicationDate":"2026-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12978539/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147446078","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Francisella tularensis virulence relies on a conserved putative catalytic triad within the Type VI secretion system component PdpC. 土拉弗朗西斯菌的毒力依赖于六型分泌系统成分PdpC中保守的推定催化三联体。

IF 4.2

FEMS microbes Pub Date : 2026-02-14 eCollection Date: 2026-01-01 DOI: 10.1093/femsmc/xtag009

Jeanette E Bröms, Igor Golovliov, Athar Alam, Shaochun Zhu, André Mateus, Thomas Henry, Anders Sjöstedt

{"title":"Francisella tularensis virulence relies on a conserved putative catalytic triad within the Type VI secretion system component PdpC.","authors":"Jeanette E Bröms, Igor Golovliov, Athar Alam, Shaochun Zhu, André Mateus, Thomas Henry, Anders Sjöstedt","doi":"10.1093/femsmc/xtag009","DOIUrl":"10.1093/femsmc/xtag009","url":null,"abstract":"Gram-negative bacteria utilize type VI secretion systems (T6SS) for microbial competition and host interaction. While most pathogens rely on the canonical T6SSi, Francisella species uniquely possess T6SSii. The highly virulent human pathogen Francisella tularensis harbors a distinct T6SSii variant that includes pdpC, encoding a putative effector protein. Bioinformatic analysis revealed a conserved amino acid triad in PdpC, homologous to motifs found in Make Caterpillars Floppy family toxins. To investigate the functional relevance of this triad, site-directed mutagenesis was performed in the live vaccine strain of F. tularensis, substituting each residue with alanine. Mutants showed impaired phagosomal escape, reduced intracellular replication, and marked attenuation in the mouse infection model. Equivalent mutations introduced into F. novicida, a model for T6SS-mediated secretion, confirmed the triad's importance. Mass spectrometry analysis demonstrated that PdpC is secreted in a T6SS-dependent manner. Importantly, the mutations did not affect secretion, and deletion of pdpC did not alter the overall secretion profile. These findings indicate that the conserved triad is essential for PdpC's effector function but dispensable for its secretion. This study highlights a critical motif required for Francisella virulence and provides new insights into the specialized mechanisms of T6SSii effectors.","PeriodicalId":73024,"journal":{"name":"FEMS microbes","volume":"7 ","pages":"xtag009"},"PeriodicalIF":4.2,"publicationDate":"2026-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12955703/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147357895","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Uridine diphosphate N-acetylglucosamine homeostasis via CgNgk1 kinase modulates chitin levels and cell-wall integrity in Candida glabrata. CgNgk1激酶介导的尿苷二磷酸n -乙酰氨基葡萄糖稳态调节念珠菌几丁质水平和细胞壁完整性。

IF 4.2

FEMS microbes Pub Date : 2026-02-09 eCollection Date: 2026-01-01 DOI: 10.1093/femsmc/xtag007

Rio Yamada, Hironobu Nakayama, Sumire Yoshikawa, Shuichi Karita, Midori Umekawa

{"title":"Uridine diphosphate N-acetylglucosamine homeostasis via CgNgk1 kinase modulates chitin levels and cell-wall integrity in Candida glabrata.","authors":"Rio Yamada, Hironobu Nakayama, Sumire Yoshikawa, Shuichi Karita, Midori Umekawa","doi":"10.1093/femsmc/xtag007","DOIUrl":"10.1093/femsmc/xtag007","url":null,"abstract":"Candida glabrata is a clinically significant cause of candidemia, yet how it supplies uridine diphosphate-N-acetylglucosamine (UDP-GlcNAc) for cell-wall chitin synthesis remains unclear. Here, we identify an N-acetylglucosamine (GlcNAc) kinase encoded by CAGL0M00682g and designated CgNgk1. In vitro, purified CgNgk1 preferentially phosphorylated GlcNAc with markedly higher catalytic efficiency than other sugars and accepted multiple nucleoside triphosphates, including ATP, as phosphoryl donors. Site-directed mutagenesis indicated that Asp197 and Lys155 are required for catalysis and ATP binding, respectively. In vivo, CgNgk1 overexpression in C. glabrata increased intracellular UDP-GlcNAc in a GlcNAc dose-dependent manner, whereas the kinase-dead D197N variant had no effect. CgNgk1-mediated GlcNAc phosphorylation elevated cell-wall chitin and heightened sensitivity to sodium dodecyl sulfate, heat, and low pH, but did not affect β-1,3-glucan-related phenotypes such as zymolyase or caspofungin sensitivity. Under GlcNAc supplementation, CgNgk1-overexpression specifically decreased cellular susceptibility to flucytosine, while responses to voriconazole and amphotericin B were unchanged. Overexpression of the putative hexosamine-pathway regulator CgIsr1 lowered intracellular UDP-GlcNAc, consistent with an intact endogenous pathway. These findings demonstrate that imported GlcNAc is routed via CgNgk1 to UDP-GlcNAc to promote chitin biosynthesis, and that quantitative control of this route shapes cell-wall integrity and modulates responses to host-relevant stresses and antifungal agents.","PeriodicalId":73024,"journal":{"name":"FEMS microbes","volume":"7 ","pages":"xtag007"},"PeriodicalIF":4.2,"publicationDate":"2026-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12947576/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147328392","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A machine learning approach elucidates spatial patterns of environmental properties driving microbial composition over Santos Basin, South Atlantic. 一种机器学习方法阐明了南大西洋桑托斯盆地上驱动微生物组成的环境特性的空间模式。

IF 4.2

FEMS microbes Pub Date : 2026-02-09 eCollection Date: 2026-01-01 DOI: 10.1093/femsmc/xtag008

Julio Cezar Fornazier Moreira, Flúvio Modolon, Natascha Menezes Bergo, Danilo Candido Vieira, Gustavo Fonseca, Francielli Vilela Peres, Rebeca Graciela Matheus Lizárraga, Diana Carolina Duque-Castaño, Alice de Moura Emilio, Augusto Miliorini Amendola, Renato Gamba Romano, Mateus Gustavo Chuqui, Fabiana S Paula, Daniel Leite Moreira, Célio Roberto Jonck, Amanda Bendia, Frederico Pereira Brandini, Vivian Helena Pellizari

{"title":"A machine learning approach elucidates spatial patterns of environmental properties driving microbial composition over Santos Basin, South Atlantic.","authors":"Julio Cezar Fornazier Moreira, Flúvio Modolon, Natascha Menezes Bergo, Danilo Candido Vieira, Gustavo Fonseca, Francielli Vilela Peres, Rebeca Graciela Matheus Lizárraga, Diana Carolina Duque-Castaño, Alice de Moura Emilio, Augusto Miliorini Amendola, Renato Gamba Romano, Mateus Gustavo Chuqui, Fabiana S Paula, Daniel Leite Moreira, Célio Roberto Jonck, Amanda Bendia, Frederico Pereira Brandini, Vivian Helena Pellizari","doi":"10.1093/femsmc/xtag008","DOIUrl":"10.1093/femsmc/xtag008","url":null,"abstract":"Marine microbial communities are vital to biogeochemical cycling, yet their dynamics in regions of ecological and industrial significance, such as the Santos Basin (SB), Brazil's largest offshore oil-producing basin, remain poorly resolved. To address this gap, we combined 16S rRNA amplicon sequencing, flow cytometry, and a hybrid machine learning framework (Self-Organizing Maps and Random Forest) to analyze microbial community stratification across pelagic depths in the SB. We identified five depth-specific microbial associations predicted with 86% accuracy, driven primarily by temperature, salinity, water density, and nutrient availability. Shallow epipelagic and mesopelagic zones were dominated by temperature-driven assemblages, while deeper bathypelagic communities responded to salinity and density gradients. Temporal and spatial patterns further highlighted the influence of regional oceanographic processes, including the Cabo Frio upwelling and Rio de la Plata plume. Microbial diversity increased with depth, contrasting with higher cell abundances in nutrient-rich shallow waters. We provided new insights into the relative importance of oceanographic processes, suggesting that vertical stratification and regional hydrography may play a more central role shaping microbial communities than previously recognized. We also established a predictive framework for microbial dynamics in marine ecosystems, with direct implications for assessing anthropogenic impacts in industrially active regions like the SB.","PeriodicalId":73024,"journal":{"name":"FEMS microbes","volume":"7 ","pages":"xtag008"},"PeriodicalIF":4.2,"publicationDate":"2026-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12951518/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147349860","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Enhanced antibacterial activity of antimicrobial peptide-antibiotic combinations against multidrug-resistant bacteria. 抗菌肽-抗生素联合抗多药耐药菌活性增强研究。

IF 4.2

FEMS microbes Pub Date : 2026-02-04 eCollection Date: 2026-01-01 DOI: 10.1093/femsmc/xtag003

Muhammad Talha, Cesar Augusto Roque-Borda

{"title":"Enhanced antibacterial activity of antimicrobial peptide-antibiotic combinations against multidrug-resistant bacteria.","authors":"Muhammad Talha, Cesar Augusto Roque-Borda","doi":"10.1093/femsmc/xtag003","DOIUrl":"10.1093/femsmc/xtag003","url":null,"abstract":"The rapid emergence of multidrug-resistant (MDR) bacteria has severely compromised the efficacy of conventional antibiotics and intensified the global antimicrobial resistance crisis. Antimicrobial peptides (AMPs) have attracted considerable interest as adjunctive agents due to their membrane-active mechanisms and immunomodulatory properties; however, their clinical use as monotherapy remains limited by instability, toxicity, and pharmacokinetic constraints. Combining AMPs with conventional antibiotics has emerged as a promising strategy to enhance antibacterial efficacy, restore antibiotic susceptibility, and modulate resistance development. This review critically examines the mechanistic basis of AMP-antibiotic synergy, integrating evidence from in vitro and in vivo studies. Particular emphasis is placed on determinants that govern synergistic outcomes, including membrane permeability, porin-dependent antibiotic uptake, resistance-associated adaptations, and host-related factors that cannot be captured in vitro. In addition, we discuss key translational barriers limiting clinical implementation, such as immune modulation, pharmacokinetic mismatch, peptide instability, and strain-dependent variability in synergistic responses. By linking molecular mechanisms to experimental and translational outcomes, this review provides a focused framework for rational design and optimization of AMP-antibiotic combination therapies against MDR bacterial infections.","PeriodicalId":73024,"journal":{"name":"FEMS microbes","volume":"7 ","pages":"xtag003"},"PeriodicalIF":4.2,"publicationDate":"2026-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12947588/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147328436","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

In vitro growth of Toxoplasma gondii tachyzoites on different host cell lines selects for changes in efficiency of invasion and parasite surface antigen gene expression. 刚地弓形虫速殖子在不同宿主细胞系上的体外生长选择了入侵效率和寄生虫表面抗原基因表达的变化。

IF 4.2

FEMS microbes Pub Date : 2026-02-02 eCollection Date: 2026-01-01 DOI: 10.1093/femsmc/xtag006

Adit Naor, John Boothroyd

{"title":"In vitro growth of Toxoplasma gondii tachyzoites on different host cell lines selects for changes in efficiency of invasion and parasite surface antigen gene expression.","authors":"Adit Naor, John Boothroyd","doi":"10.1093/femsmc/xtag006","DOIUrl":"10.1093/femsmc/xtag006","url":null,"abstract":"Toxoplasma gondii is remarkable for its intermediate host range, which includes most warm-blooded animals so far tested. Being such a generalist poses challenges for how the parasite can be optimized for growth in cell types that might be radically different in their metabolism and other aspects, including host defenses and microenvironments. To explore how the parasite might adapt to finding itself in a different host, we started with a Type II line of T. gondii (ME49) that had been grown for at least the past 20 years exclusively in vivo. This line was then used to repeatedly infect two cell lines in vitro, human foreskin fibroblasts and Madin-Darby bovine kidney cells. After at least 70 such passages in one or other host cell type, the resulting lines were compared with respect to growth differences, secretion of an important adhesin (MIC2), and transcriptome. The results showed that passage on these two host cell lines results in profound and reproducible differences in parasite phenotype, including attachment/invasion, MIC2 secretion, and gene expression. The transcriptomic differences were especially pronounced for parasite surface antigen genes. The implications of these results for how T. gondii deals with its breadth of possible intermediate hosts are discussed.","PeriodicalId":73024,"journal":{"name":"FEMS microbes","volume":"7 ","pages":"xtag006"},"PeriodicalIF":4.2,"publicationDate":"2026-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12908928/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146215093","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Traditional fermented foods of Indonesia harbour functionally redundant but phylogenetically diverse taxa. 印度尼西亚传统发酵食品具有功能冗余但系统发育多样的分类群。

IF 4

FEMS microbes Pub Date : 2026-01-22 eCollection Date: 2026-01-01 DOI: 10.1093/femsmc/xtag005

Wisnu Adi Wicaksono, Elma Zukancic, Matevz Zlatnar, Antonius Suwanto, Gabriele Berg

{"title":"Traditional fermented foods of Indonesia harbour functionally redundant but phylogenetically diverse taxa.","authors":"Wisnu Adi Wicaksono, Elma Zukancic, Matevz Zlatnar, Antonius Suwanto, Gabriele Berg","doi":"10.1093/femsmc/xtag005","DOIUrl":"10.1093/femsmc/xtag005","url":null,"abstract":"Fermented foods represent complex microbial ecosystems that contribute to food quality, functionality, and potential health benefits, yet many traditional fermented foods remain poorly characterized. The aim of this study was to study microbial diversity, and functional potential of underexplored traditional Indonesian fermented food. The fermented products displayed substantial variation in bacterial richness, ranging from 65 to 614 bacterial amplicon sequence variants across samples. The microbial communities were dominated by bacterial taxa affiliated with the orders Bacillales and Lactobacillales, alongside fungal taxa from the order Mucorales. The plant-based products i.e. tape ketan and tape singkong had a higher bacterial abundance but lower diversity than animal-based terasi. We found significant correlations between bacterial and fungal communities dominated by positive cooccurrence patterns and highly complex networks especially in terasi. Each food product was characterized by a unique functional profile of genes linked to beneficial metabolic functions (biosynthesis of bacteriocins, short-chain fatty acids, and vitamins) but tape ketan samples demonstrated the highest diversity and abundance of them. Metagenome assembled genomes reflect a high diversity of health beneficial properties as well as substrate-specific degradation capabilities. Traditional Indonesian fermented foods harbour functionally redundant but phylogenetically diverse taxa offering a potential source for probiotic traits and functional food development.","PeriodicalId":73024,"journal":{"name":"FEMS microbes","volume":"7 ","pages":"xtag005"},"PeriodicalIF":4.0,"publicationDate":"2026-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12875122/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146144781","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Marginal link between sociality and gut microbiome in disparate mammalian hosts. 在不同的哺乳动物宿主中，社会性和肠道微生物组之间的边缘联系。

IF 4

FEMS microbes Pub Date : 2026-01-22 eCollection Date: 2026-01-01 DOI: 10.1093/femsmc/xtag004

Eleonore Lebeuf-Taylor, Karl Cottenie

引用次数: 0

The role of Fusobacterium nucleatum in the tumour microenvironment and carcinogenesis of oral and colonic malignancies. 核梭杆菌在口腔和结肠恶性肿瘤微环境和癌变中的作用。

IF 4

FEMS microbes Pub Date : 2026-01-10 eCollection Date: 2026-01-01 DOI: 10.1093/femsmc/xtag002

Elisabetha Larionova, Gary P Moran

{"title":"The role of Fusobacterium nucleatum in the tumour microenvironment and carcinogenesis of oral and colonic malignancies.","authors":"Elisabetha Larionova, Gary P Moran","doi":"10.1093/femsmc/xtag002","DOIUrl":"10.1093/femsmc/xtag002","url":null,"abstract":"The intra-tumoural microbiome is an increasing area of research with potential benefits in cancer diagnostics and treatment development. Numerous studies have implicated Fusobacterium nucleatum, a member of the oral microbiota, in the development, immune evasion, and dissemination of oral and colorectal tumours. Although F. nucleatum is yet to be classified as a cause or consequence of cancer, reports indicate the microorganism's involvement in DNA damage, pathologic glucose uptake, and cellular proliferation. This accumulation of genetic instability is consistent with the multistep nature of malignant neoplasm progression. Virulence factors of F. nucleatum were shown to maintain an unresolved inflammatory state and impair the normal function of immune cells. The accompanying pro-inflammatory conditions facilitate vasculature remodelling, expediting tumour expansion, through a range of mechanisms. Pro-metastatic epithelial-to-mesenchymal transition and changes in gene expression have been observed in cancer cells upon F. nucleatum infection, suggesting an association with poorer prognosis. As a frequently encountered microorganism in the oral and colorectal intra-tumoural microbiome, F. nucleatum represents an intriguing, yet cautious research prospect with opportunities for novel prevention and therapeutic strategies. The objective of this work is to review the relevant evidence, taking into account the complexity of the tumour microenvironment.","PeriodicalId":73024,"journal":{"name":"FEMS microbes","volume":"7 ","pages":"xtag002"},"PeriodicalIF":4.0,"publicationDate":"2026-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12853310/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146109005","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Radiation-response in Deinococcus bacteria: characterization of the transient IrrE-DdrO heterodimer complex. Deinococcus细菌的辐射响应：瞬态IrrE-DdrO异二聚体复合物的表征。

IF 4

FEMS microbes Pub Date : 2026-01-06 eCollection Date: 2026-01-01 DOI: 10.1093/femsmc/xtag001

Alicia Reuzeau, Océane Reille, Soazig Malesinski, Frédéric Allemand, Tiffanie Barré, David Lemaire, Nathalie Sibille, Arjan de Groot, Laurence Blanchard

{"title":"Radiation-response in Deinococcus bacteria: characterization of the transient IrrE-DdrO heterodimer complex.","authors":"Alicia Reuzeau, Océane Reille, Soazig Malesinski, Frédéric Allemand, Tiffanie Barré, David Lemaire, Nathalie Sibille, Arjan de Groot, Laurence Blanchard","doi":"10.1093/femsmc/xtag001","DOIUrl":"10.1093/femsmc/xtag001","url":null,"abstract":"Radiation resistance in Deinococcus requires an SOS-independent response mechanism, controlled by M78 family (COG2856) metallopeptidase IrrE and XRE family transcriptional repressor DdrO, to induce expression of DNA repair genes after exposure to radiation. DdrO must form dimers to bind target DNA sites. IrrE inactivates DdrO by cleaving the C-terminal dimerization domain of DdrO. However, the molecular basis of the interaction between IrrE and DdrO is still unknown. Here, we showed that IrrE is monomeric in solution and forms heterodimers with DdrO, with the N-terminal DNA-binding domain of DdrO contributing to the interaction. We further revealed that the initially isolated radiation-sensitive irrE mutant strain encodes an oxidation-sensitive IrrE protein affected in DdrO cleavage. Predicted COG2856/XRE regulatory protein pairs are present in many environmental, pathogenic, and industrial bacteria. Single-stranded DNA enhanced the cleavage activity of IrrE from Deinococcus as well as from closely related Marinithermus and Oceanithermus species, but not of the distant homologs ImmA from Bacillus subtilis and Rir from Streptococcus thermophilus. The formation of a heterotrimer containing IrrE, DdrO, and single-stranded DNA was also demonstrated. Together, these findings provide new insights into the molecular interplay between the key regulators IrrE and DdrO.","PeriodicalId":73024,"journal":{"name":"FEMS microbes","volume":"7 ","pages":"xtag001"},"PeriodicalIF":4.0,"publicationDate":"2026-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12828697/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146055232","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0