Behrens S, Maier R, de Cock H, Schmid F X, Gross C A
Departments of Stomatology and Microbiology, University of California, San Francisco, 513 Parnassus Avenue, CA 94143, USA.
EMBO J. 2001 Jan 15;20(1-2):285-94. doi: 10.1093/emboj/20.1.285.
The Escherichia coli periplasmic peptidyl-prolyl isomerase (PPIase) SurA is involved in the maturation of outer membrane porins. SurA consists of a substantial N-terminal region, two iterative parvulin-like domains and a C-terminal tail. Here we show that a variant of SurA lacking both parvulin-like domains exhibits a PPIase-independent chaperone-like activity in vitro and almost completely complements the in vivo function of intact SurA. SurA interacts preferentially (>50-fold) with in vitro synthesized porins over other similarly sized proteins, leading us to suggest that the chaperone-like function of SurA preferentially facilitates maturation of outer membrane proteins.
大肠杆菌周质肽基脯氨酰异构酶（PPIase）SurA参与外膜孔蛋白的成熟过程。SurA由一个较大的N端区域、两个重复的类细小菌素结构域和一个C端尾巴组成。在此我们表明，缺失两个类细小菌素结构域的SurA变体在体外表现出一种不依赖PPIase的伴侣样活性，并且几乎能完全互补完整SurA的体内功能。与其他大小相似的蛋白质相比，SurA与体外合成的孔蛋白优先相互作用（>50倍），这使我们认为SurA的伴侣样功能优先促进外膜蛋白的成熟。
