Uncovering Roles of Streptococcus gordonii SrtA-Processed Proteins in the Biofilm Lifestyle.
Uncovering Roles of Streptococcus gordonii SrtA-Processed Proteins in the Biofilm Lifestyle.
复制标题
揭示戈登链球菌 SrtA 加工蛋白在生物膜生活方式中的作用。
DOI：
10.1128/jb.00544-20
复制
发表时间：
2020
影响因子：
3.2
通讯作者：
Herzberg,MarkC
中科院分区：
文献类型：
--
作者：
Nairn,BrittanyL;Lee,GraceT;Chumber,AshwaniK;Steck,PatrickR;Mire,MahmoudO;Lima,BrunoP;Herzberg,MarkC
戈登链球菌是一种常见的口腔微生物。戈登葡萄球菌在口腔中无害，是一种机会性病原体。戈登葡萄球菌使用表面黏附蛋白(粘附素)附着在身体表面，粘附素对随后生物膜群落的形成至关重要。像大多数革兰氏阳性细菌一样，含有C端LPXTG基序切割序列的戈登葡萄球菌表面蛋白被排序酶A(SrtA)处理，成为共价附着在细胞壁上。为了研究srtA处理蛋白家族的功能多样性和冗余性，对26个可能的srtA处理蛋白分别构建了戈登链霉菌DL1无标记缺失突变体文库。对每个文库成员在富含介质中的生长、塑料、唾液和唾液部分上生物膜的形成、细胞表面疏水性(CSH)、血凝以及与AneX活菌斑生物膜群落的整合进行了评估。将文库成员与非SrtA加工的粘附素ABPA和ABB进行比较。虽然在富培养条件下没有观察到明显的生长差异，但许多戈登氏链球菌LPXTG/A蛋白影响了一个或多个底物上的生物膜的形成。几个突变体在血凝、疏水性或在EX活斑模型中的适合性方面显示出显著的差异。从鉴定这些蛋白中的冗余和独特功能来看，LPXTG/A蛋白之间存在明显的功能分层。戈登氏链霉菌与其环境的相互作用取决于细胞壁蛋白的补充性。这些细胞壁蛋白的一部分需要由酶分类酶A(SrtA)处理。鉴定srtA加工的蛋白质及其功能特性将有助于社区更好地了解戈登葡萄球菌如何与周围环境(包括其他微生物)接触，整合到菌斑群落中，附着在牙齿表面，并通过血液传播导致血液传播。本研究通过建立无标记缺失突变体文库，鉴定了26种可能的经srtA处理的蛋白质。文库受到功能筛选的影响，选择这些筛选是为了更好地了解戈登氏链球菌的生理和发病机制的关键方面。
Streptococcus gordonii is a commensal oral organism. Harmless in the oral cavity, S. gordonii is an opportunistic pathogen. S. gordonii adheres to body surfaces using surface adhesive proteins (adhesins), which are critical to subsequent formation of biofilm communities. As in most Gram-positive bacteria, S. gordonii surface proteins containing the C-terminal LPXTG motif cleavage sequence are processed by sortase A (SrtA) to become covalently attached to the cell wall. To characterize the functional diversity and redundancy in the family of SrtA-processed proteins, an S. gordonii DL1 markerless deletion mutant library was constructed of each of the 26 putative SrtA-processed proteins. Each library member was evaluated for growth in rich medium, biofilm formation on plastic, saliva and salivary fractions, cell surface hydrophobicity (CSH), hemagglutination, and integration into anex vivoplaque biofilm community. Library members were compared to the non-SrtA-processed adhesins AbpA and AbpB. While no major growth differences in rich medium were observed, many S. gordonii LPXTG/A proteins impacted biofilm formation on one or more of the substrates. Several mutants showed significant differences in hemagglutination, hydrophobicity, or fitness in theex vivoplaque model. From the identification of redundant and unique functions in thesein vitroandex vivosystems, functional stratification among the LPXTG/A proteins is apparent.IMPORTANCES. gordonii interactions with its environment depend on the complement of cell wall proteins. A subset of these cell wall proteins requires processing by the enzyme sortase A (SrtA). The identification of SrtA-processed proteins and their functional characterization will help the community to better understand how S. gordonii engages with its surroundings, including other microbes, integrates into the plaque community, adheres to the tooth surface, and hematogenously disseminates to cause blood-borne infections. This study identified 26 putative SrtA-processed proteins through creation of a markerless deletion mutant library. The library was subject to functional screens that were chosen to better understand key aspects of S. gordonii physiology and pathogenesis.