Structural basis for Zn2+-dependent intercellular adhesion in staphylococcal biofilms
Structural basis for Zn2+-dependent intercellular adhesion in staphylococcal biofilms
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DOI：
10.1073/pnas.1208134110
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发表时间：
2013-01-15
影响因子：
11.1
通讯作者：
Herr, Andrew B.
中科院分区：
文献类型：
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作者：
Conrady, Deborah G.;Wilson, Jeffrey J.;Herr, Andrew B.
葡萄球菌，包括表皮葡萄球菌和金黄色葡萄球菌，引起慢性生物膜相关感染。同源蛋白Aap和SasG介导S.表皮葡萄球菌和表皮葡萄球菌。金黄色葡萄球菌。这些蛋白质在Zn 2+存在下的自缔合导致细胞之间形成广泛的粘附接触。本研究报告的晶体结构的Zn 2+结合的结构从自缔合区域的AAP。几个不寻常的结构特征包括伸长的β-片层，其两面都暴露在溶剂中，并且缺乏典型的疏水核心。Zn 2 +-依赖的二聚体被观察到在三个不同的晶体形式，形成通过多晶配位的Zn 2+的反式跨越二聚体界面。这些结构说明了一个长的，灵活的表面蛋白质是如何能够在不利的环境条件下形成紧密的细胞间粘附位点。
Staphylococcal bacteria, including Staphylococcus epidermidis and Staphylococcus aureus, cause chronic biofilm-related infections. The homologous proteins Aap and SasG mediate biofilm formation in S. epidermidis and S. aureus, respectively. The self-association of these proteins in the presence of Zn2+ leads to the formation of extensive adhesive contacts between cells. This study reports the crystal structure of a Zn2+-bound construct from the self-associating region of Aap. Several unusual structural features include elongated beta-sheets that are solvent-exposed on both faces and the lack of a canonical hydrophobic core. Zn2+-dependent dimers are observed in three distinct crystal forms, formed via pleomorphic coordination of Zn2+ in trans across the dimer interface. These structures illustrate how a long, flexible surface protein is able to form tight intercellular adhesion sites under adverse environmental conditions.