Functional consequences of B-repeat sequence variation in the staphylococcal biofilm protein Aap: deciphering the assembly code.
Functional consequences of B-repeat sequence variation in the staphylococcal biofilm protein Aap: deciphering the assembly code.
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葡萄球菌生物膜蛋白 Aap 中 B 重复序列变异的功能后果：破译汇编代码。
DOI：
10.1042/bcj20160675
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发表时间：
2017
期刊：
影响因子：
--
通讯作者：
Herr,AndrewB
中科院分区：
文献类型：
--
作者：
Shelton,CatherineL;Conrady,DeborahG;Herr,AndrewB
表皮葡萄球菌是一种机会致病菌，可形成坚固的生物膜，使细菌对抗生素作用和免疫应答产生抗性。表皮葡萄球菌生物膜中的细胞间粘附由细胞壁相关积累相关蛋白（Aap）介导，通过锌介导的其B重复区的自组装。该区域包含多达17个几乎相同的重复序列，每个重复序列被认为是功能等同的。然而，Aap B-重复序列以两种亚型存在，由一组共有或变体氨基酸定义。这些可变残基位于锌结合（和二聚化）位点附近和B重复折叠的稳定性决定簇。我们已经表征了四个B-重复结构，以评估两个Aap B-重复亚型的功能相关性。分析性超离心实验表明，具有变体序列的构建体显示减少或不存在Zn 2+诱导的二聚化。同样，圆二色性热变性实验表明，变异序列可以显着稳定的折叠，这取决于其在构建体中的位置。三个构建体的晶体结构揭示了来自变体序列的侧链形成了可以稳定折叠的广泛的键合网络。此外，改变带电残基之间的共识和变体序列的分布改变的静电电位在附近的Zn 2+结合位点，提供了一个机制解释的损失锌诱导的二聚化的变体构建体。这些数据表明，一个汇编代码，定义了优选的寡聚化模式的B-重复区域的AAP和滑动抓地力模型的初始接触，然后由坚定的细胞间粘附在生物膜形成。
Staphylococcus epidermidisis an opportunistic pathogen that can form robust biofilms that render the bacteria resistant to antibiotic action and immune responses. Intercellular adhesion inS. epidermidisbiofilms is mediated by the cell wall-associated accumulation-associated protein (Aap), via zinc-mediated self-assembly of its B-repeat region. This region contains up to 17 nearly identical sequence repeats, with each repeat assumed to be functionally equivalent. However, Aap B-repeats exist as two subtypes, defined by a cluster of consensus or variant amino acids. These variable residues are positioned near the zinc-binding (and dimerization) site and the stability determinant for the B-repeat fold. We have characterized four B-repeat constructs to assess the functional relevance of the two Aap B-repeat subtypes. Analytical ultracentrifugation experiments demonstrated that constructs with the variant sequence show reduced or absent Zn2+-induced dimerization. Likewise, circular dichroism thermal denaturation experiments showed that the variant sequence could significantly stabilize the fold, depending on its location within the construct. Crystal structures of three of the constructs revealed that the side chains from the variant sequence form an extensive bonding network that can stabilize the fold. Furthermore, altered distribution of charged residues between consensus and variant sequences changes the electrostatic potential in the vicinity of the Zn2+-binding site, providing a mechanistic explanation for the loss of zinc-induced dimerization in the variant constructs. These data suggest an assembly code that defines preferred oligomerization modes of the B-repeat region of Aap and a slip-grip model for initial contact followed by firm intercellular adhesion during biofilm formation.
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影响因子：
3.1
作者：
Fey PD;Olson ME
通讯作者：
Olson ME
DOI：
10.1073/pnas.1208134110
发表时间：
2013-01-15
影响因子：
11.1
作者：
Conrady, Deborah G.;Wilson, Jeffrey J.;Herr, Andrew B.
通讯作者：
Herr, Andrew B.
影响因子：
3.1
作者：
Schommer, Nina N.;Christner, Martin;Rohde, Holger
通讯作者：
Rohde, Holger
影响因子：
2.8
作者：
Bowden, MG;Chen, W;Höök, M
通讯作者：
Höök, M
影响因子：
3.6
作者：
Larru, Beatriz;Gong, Wu;Gerber, Jeffrey S.
通讯作者：
Gerber, Jeffrey S.