National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA.
Structure. 2012 Jul 3;20(7):1233-43. doi: 10.1016/j.str.2012.04.011. Epub 2012 May 31.
Intimins and invasins are virulence factors produced by pathogenic Gram-negative bacteria. They contain C-terminal extracellular passenger domains that are involved in adhesion to host cells and N-terminal β domains that are embedded in the outer membrane. Here, we identify the domain boundaries of an E. coli intimin β domain and use this information to solve its structure and the β domain structure of a Y. pseudotuberculosis invasin. Both β domain structures crystallized as monomers and reveal that the previous range of residues assigned to the β domain also includes a protease-resistant domain that is part of the passenger. Additionally, we identify 146 nonredundant representative members of the intimin/invasin family based on the boundaries of the highly conserved intimin and invasin β domains. We then use this set of sequences along with our structural data to find and map the evolutionarily constrained residues within the β domain.
黏附素和侵袭素是革兰氏阴性致病菌产生的毒力因子。它们含有 C 末端细胞外的载体结构域，参与与宿主细胞的黏附，以及 N 末端嵌入外膜的β结构域。在这里，我们确定了大肠杆菌黏附素β结构域的结构域边界，并利用这一信息来解析其结构和假结核耶尔森氏菌侵袭素的β结构域。这两种β结构域都以单体形式结晶，并揭示了之前被分配到β结构域的残基范围还包括一个蛋白酶抗性结构域，该结构域是载体的一部分。此外，我们根据高度保守的黏附素和侵袭素β结构域的边界，基于 146 个非冗余的代表性黏附素/侵袭素家族成员，来识别它们。然后，我们使用这组序列和我们的结构数据来发现并映射β结构域内受进化约束的残基。
