Solution NMR Study of a Cytochrome C Mutant(A44C) with Enhanced Apoptotic Activity

Abstract

FlgL, respectively. FliJ is a general chaperone that assists and regulates the export process. FlhA and FlhB constitute the export gate and determines the hierarchy of the export process. Despite detailed understanding of the morphology of flagellum, flagella export process is poorly understood. We have determined the solution structure of FliT in its apo form along with its complex with FliD, FliI, and FliJ. Solution structure of FliT differs from its crystal structure and explains the regulatory role of FliT. FliT stays in an auto-inhibitory form in the absence of substrates to avoid any unwanted interaction with export gate. Substrate binding activates FliT-substrate complex to bind to the export gate. This targeting mechanism of FliT is appeared to be shared among all export chaperones, FlgN and FliS. We further characterized the interactions among export chaperones and showed that strict binding sequence among chaperones determines chaperone recycling process and regulate subsequent export events.