The catalytic activity of protein-disulfide isomerase requires a conformationally flexible molecule.

ABSTRACT: Protein-disulfide isomerase (PDI) catalyzes the formation of the correct pattern of disulfide bonds in secretory proteins. A low resolution crystal structure of yeast PDI described here reveals large scale conformational changes compared with the initially reported structure, indicating that PDI is a highly flexible molecule with its catalytic domains, a and a', representing two mobile arms connected to a more rigid core composed of the b and b' domains. Limited proteolysis revealed that the linker between the a domain and the core is more susceptible to degradation than that connecting the a' domain to the core. By restricting the two arms with inter-domain disulfide bonds, the molecular flexibility of PDI, especially that of its a domain, was demonstrated to be essential for the enzymati

SUBMITTER: Tian G 

PROVIDER: S-EPMC2586259 | biostudies-literature | 2008 Nov

REPOSITORIES: biostudies-literature