Tripartite motif ligases catalyze polyubiquitin chain formation through a cooperative allosteric mechanism.

ABSTRACT: Ligation of polyubiquitin chains to proteins is a fundamental post-translational modification, often resulting in targeted degradation of conjugated proteins. Attachment of polyubiquitin chains requires the activities of an E1 activating enzyme, an E2 carrier protein, and an E3 ligase. The mechanism by which polyubiquitin chains are formed remains largely speculative, especially for RING-based ligases. The tripartite motif (TRIM) superfamily of ligases functions in many cellular processes including innate immunity, cellular localization, development and differentiation, signaling, and cancer progression. The present results show that TRIM ligases catalyze polyubiquitin chain formation in the absence of substrate, the rates of which can be used as a functional readout of enzyme function. In

SUBMITTER: Streich FC 

PROVIDER: S-EPMC3605639 | biostudies-literature | 2013 Mar

REPOSITORIES: biostudies-literature