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Biological and structural diversity of bacterial type IV secretion systems

IV型细菌分泌系统的生物学和结构多样性

基本信息

批准号：
10613935
负责人：
PETER j. CHRISTIE
金额：
$ 46.7万
依托单位：
UNIVERSITY OF TEXAS HLTH SCI CTR HOUSTON
依托单位国家：
美国
项目类别：
财政年份：
2019
资助国家：
美国
起止时间：
2019-06-07 至 2024-04-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10613935
关键词：
ATP phosphohydrolase Antibiotic Resistance Antibiotic Therapy Architecture Back Bacteria Bacterial Adhesins Bacterial Genome Binding Biochemical Biochemistry Biogenesis Biological Biological Models Cell surface Cells Chromosomes Collaborations Communities Cryo-electron tomography Cryoelectron Microscopy Cytology DNA Development Disease Progression Dissociation Emerging Technologies Escherichia coli Eukaryotic Cell F Factor Fluorescence Microscopy Fractionation Genes Genetic Genetic Recombination Genetic study Human In Situ In Vitro Infection Mediating Medical Membrane Microbial Biofilms Mobile Genetic Elements Molecular Partner in relationship Pilum Population Positioning Attribute Process Production Proteins Public Health Reaction Resolution Role Route Science Sex Pili Shapes Signal Transduction Structure System Therapeutic Intervention Type IV Secretion System Pathway Virulence Factors Visualization biophysical techniques defined contribution fitness in vivo insight macromolecule multidisciplinary nanomachine new therapeutic target novel particle pathogen recruit therapy design trait transmission process ultra high resolution vector

项目摘要

PROJECT SUMMARY The transmission of macromolecules across biological membranes is a fundamental process in all cells. In the earliest studies of genetic exchange in bacteria dating back to the 1940's, the F plasmid (then termed `sex factor') was shown to self-transfer and, through recombination, mediate the transfer of the entire E. coli chromosome to recipient bacteria. In the ensuing ~75 years, studies established the broad medical importance of F and other mobile genetic elements (MGEs) in the shaping of bacterial genomes and as vectors for dissemination of antibiotic resistance and other fitness traits among bacterial populations. MGEs also encode conjugative pili or other cell surface adhesins, which promote intercellular contacts necessary for DNA transfer and establishment robust, antibiotic-resistant biofilm communities. MGEs are transmitted intercellularly through nanomachines termed type IV secretion systems (T4SSs). The T4SSs are present in most if not all bacterial species, where they have functionally diversified into two large subfamilies, the DNA transfer or conjugation systems and the `effector translocators' that translocate effector proteins into eukaryotic host cells as a critical feature of infection processes. Over the past 27 years, my group has used molecular, genetic and biochemical approaches to identify many mechanistic and architectural features of T4SSs, including the first view of the translocation route for a DNA substrate through a T4SS. We have consistently implemented emerging technologies, and just within the past 1½ years we began to solve T4SS structures at unprecedented resolution by in situ cryoelectron tomography (CryoET). These new structures are significantly advancing the field, but also are raising important new questions relating to underlying mechanisms and signals governing i) assembly of envelope-spanning T4SS channels and conjugative pili, ii) early-stage substrate recruitment and processing reactions, and iii) establishment of direct contacts (mating junctions) with bacterial and eukaryotic cells. Moving forward, we will address these fundamental questions by (1) continuing to solve novel structures encoded by the E. coli F T4SS using in situ CryoET, biochemical fractionation, super-resolution fluorescence microscopy, and single-particle CryoEM, (2) defining contributions of the newly visualized ATPase energy center positioned at the channel entrance in binding and unfolding substrates and dissociating accessory factors using in vivo and in vitro biochemistry and ultrastructural approaches, (3) exploring the roles of conjugative pili and cell surface adhesins in formation and disassembly of mating junctions using cytological, biochemical and biophysical approaches, and (4) exploiting our development of distinct model systems to identify mechanistic themes and specialized mechanisms. We will continue to draw on the expertise of our close collaborations for a `team-science' and multidisciplinary focus. Our studies will generate important new insights into the architecture, biogenesis, and mechanism of action of the T4SS superfamily. These findings will lead to major paradigm shifts in this field, and set the stage for design of intervention therapies.

项目摘要大分子的跨膜传递是所有细胞的基本过程。在细菌遗传交换的最早研究可以追溯到20世纪40年代，F质粒（当时被称为“性因子“）显示出自我转移，并通过重组介导整个E.杆菌染色体到受体细菌。在随后的75年里，研究确立了广泛的医学重要性， F和其他移动的遗传元件（MGE）在细菌基因组的形成中的作用以及作为抗生素耐药性和其他适应性特征在细菌种群中的传播。MGE还编码接合性皮利或其它细胞表面粘附素，其促进DNA转移所必需的细胞间接触并建立强大的、抗真菌的生物膜群落。MGE通过细胞间传递纳米机器称为IV型分泌系统（T4SS）。T4SS存在于大多数（如果不是所有）细菌中。物种，在那里他们有功能多样化成两个大的亚科，DNA转移或共轭系统和将效应蛋白转运到真核宿主细胞中的“效应转运子”作为一种关键的感染过程的特征。在过去的27年里，我的团队已经使用了分子，遗传和生物化学识别T4SS的许多机械和体系结构特征的方法，包括通过T4SS的DNA底物的易位途径。我们一直在实施新兴的在过去的一年半里，我们开始以前所未有的速度解决T4SS结构问题，通过原位冷冻电子断层扫描（CryoET）进行分辨率。这些新的结构正在大大推进但也提出了与以下方面有关的重要新问题：跨膜T4 SS通道和接合皮利的组装，ii）早期底物募集，和处理反应，和iii）与细菌和真核生物建立直接接触（交配连接）细胞展望未来，我们将通过以下方式解决这些基本问题：（1）继续解决新结构由E. coli F T4SS，生化分级，超分辨荧光显微镜和单粒子CryoEM，（2）定义新可视化的ATP酶能量的贡献在结合和展开基质和解离附件中位于通道入口处的中心利用体内和体外生物化学和超微结构的方法，（3）探索的作用，接合的皮利和细胞表面粘附素在使用细胞学的交配连接的形成和分解中，生物化学和生物物理方法，以及（4）利用我们开发的不同模型系统，确定机械主题和专门机制。我们将继续利用我们的专业知识密切合作，以“团队科学”和多学科为重点。我们的研究将产生重要的新的深入了解T4SS超家族的结构、生物起源和作用机制。这些发现将导致这一领域的重大范式转变，并为干预治疗的设计奠定基础。

项目成果

期刊论文数量（15）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

ssRNA phage penetration triggers detachment of the F-pilus

DOI：
10.1073/pnas.2011901117
发表时间：
2020-10-13
期刊：
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
影响因子：
11.1
作者：
Harb, Laith;Chamakura, Karthik;Zeng, Lanying
通讯作者：
Zeng, Lanying

Protein Transfer through an F Plasmid-Encoded Type IV Secretion System Suppresses the Mating-Induced SOS Response.

DOI：
10.1128/mbio.01629-21
发表时间：
2021-08-31
期刊：
mBio
影响因子：
6.4
作者：
Al Mamun AAM;Kishida K;Christie PJ
通讯作者：
Christie PJ

Structural bases for F plasmid conjugation and F pilus biogenesis in Escherichia coli

DOI：
10.1073/pnas.1904428116
发表时间：
2019-07-09
期刊：
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
影响因子：
11.1
作者：
Hu, Bo;Khara, Pratick;Christie, Peter J.
通讯作者：
Christie, Peter J.

Structure of a type IV secretion system core complex encoded by multi-drug resistance F plasmids.