Nummelin Heli, Merckel Michael C, Leo Jack C, Lankinen Hilkka, Skurnik Mikael, Goldman Adrian
Macromolecular X-ray Crystallography Group, Institute of Biotechnology, University of Helsinki, Helsinki, Finland.
EMBO J. 2004 Feb 25;23(4):701-11. doi: 10.1038/sj.emboj.7600100. Epub 2004 Feb 5.
The crystal structure of the recombinant collagen-binding domain of Yersinia adhesin YadA from Yersinia enterocolitica serotype O:3 was solved at 1.55 A resolution. The trimeric structure is composed of head and neck regions, and the collagen binding head region is a novel nine-coiled left-handed parallel beta-roll. Before the beta-roll, the polypeptide loops from one monomer to the rest, and after the beta-roll the neck region does the same, making the transition from the globular head region to the narrower stalk domain. This creates an intrinsically stable 'lock nut' structure. The trimeric form of YadA is required for collagen binding, and mutagenesis of its surface residues allowed identification of a putative collagen-binding surface. Furthermore, a new structure-sequence motif for YadA beta-roll was used to identify putative YadA-head-like domains in a variety of human and plant pathogens. Such domains may therefore be a common bacterial strategy for avoiding host response.
对来自小肠结肠炎耶尔森氏菌血清型O:3的耶尔森氏菌粘附素YadA的重组胶原结合结构域的晶体结构进行了解析，分辨率为1.55埃。三聚体结构由头部和颈部区域组成，胶原结合头部区域是一种新型的九股左手平行β-折叠。在β-折叠之前，多肽环从一个单体延伸到其他单体，在β-折叠之后，颈部区域也如此，从而实现从球状头部区域到较窄茎部结构域的过渡。这形成了一种内在稳定的“锁紧螺母”结构。YadA的三聚体形式是胶原结合所必需的，对其表面残基进行诱变可确定一个假定的胶原结合表面。此外，利用YadAβ-折叠的一种新的结构-序列基序在多种人类和植物病原体中鉴定出假定的YadA头部样结构域。因此，此类结构域可能是细菌逃避宿主反应的一种常见策略。
