Division of Structural Biology, Department of Molecular Biology, University of Salzburg, Billrothstraße 11, A-5020 Salzburg, Austria.
Biol Chem. 2011 Nov;392(11):1039-45. doi: 10.1515/BC.2011.099. Epub 2011 Aug 28.
Bacterial collagenases exhibit a multimodular domain organization. While the N-terminal collagenase unit harbors the catalytic zinc and suffices to degrade peptidic substrates, collagen substrates come in different types, explaining the requirement for accessory domains such as polycystic kidney disease (PKD)-like domains for efficient catalysis. How the recognition and unfolding of (micro-)fibrillar or triple-helical collagen is accomplished are only poorly understood. Here, we present the crystal structure of the PKD-like domain of collagenase G from Clostridium histolyticum. The β-barrel structure reveals a two-tier architecture, connected by kinked hinge segments. Together with sheet extension as a generic oligomerization mechanism, this explains the cooperativity among accessory domains as well as their adaptivity to varying substrates.
细菌胶原酶表现出多模块结构域组织。虽然 N 端胶原酶单元含有催化锌，足以降解肽基底物，但胶原蛋白底物有不同类型，这解释了需要辅助结构域（如多囊肾病 (PKD) 样结构域）才能进行有效的催化。（微）纤维或三螺旋胶原蛋白的识别和展开过程知之甚少。本文报道了来自溶组织梭菌胶原酶 G 的 PKD 样结构域的晶体结构。β-桶结构揭示了一种两层次结构，由扭曲的铰链片段连接。与作为通用寡聚化机制的薄片延伸一起，这解释了辅助结构域之间的协同作用及其对不同底物的适应性。
