Mechanistic insight into protein modification and sulfur mobilization activities of noncanonical E1 and associated ubiquitin-like proteins of Archaea.

ABSTRACT: Here we provide the first detailed biochemical study of a noncanonical E1-like enzyme with broad specificity for cognate ubiquitin-like (Ubl) proteins that mediates Ubl protein modification and sulfur mobilization to form molybdopterin and thiolated tRNA. Isothermal titration calorimetry and in vivo analyses proved useful in discovering that environmental conditions, ATP binding, and Ubl type controlled the mechanism of association of the Ubl protein with its cognate E1-like enzyme (SAMP and UbaA of the archaeon Haloferax volcanii, respectively). Further analysis revealed that ATP hydrolysis triggered the formation of thioester and peptide bonds within the Ubl:E1-like complex. Importantly, the thioester was an apparent precursor to Ubl protein modification but not sulfur mobilization. Comp

SUBMITTER: Hepowit NL 

PROVIDER: S-EPMC5053900 | biostudies-literature | 2016 Oct

REPOSITORIES: biostudies-literature