Structural and functional characterization of the monomeric U-box domain from E4B.

ABSTRACT: Substantial evidence has accumulated indicating a significant role for oligomerization in the function of E3 ubiquitin ligases. Among the many characterized E3 ligases, the yeast U-box protein Ufd2 and its mammalian homologue E4B appear to be unique in functioning as monomers. An E4B U-box domain construct (E4BU) has been subcloned, overexpressed in Escherichia coli, and purified, which enabled determination of a high-resolution NMR solution structure and detailed biophysical analysis. E4BU is a stable monomeric protein that folds into the same structure observed for other structurally characterized U-box domain homodimers. Multiple sequence alignment combined with comparative structural analysis reveals substitutions in the sequence that inhibit dimerization. The interaction between E4BU

SUBMITTER: Nordquist KA 

PROVIDER: S-EPMC2806929 | biostudies-literature | 2010 Jan

REPOSITORIES: biostudies-literature