1t1h
From Proteopedia
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NMR solution structure of the U box domain from AtPUB14, an armadillo repeat containing protein from Arabidopsis thaliana
Overview
U-box proteins, as well as other proteins involved in regulated protein, degradation, are apparently over-represented in Arabidopsis compared with, other model eukaryotes. The Arabidopsis protein AtPUB14 contains a typical, U-box domain followed by an Armadillo repeat region, a domain organization, that is frequently found in plant U-box proteins. In vitro ubiquitination, assays demonstrated that AtPUB14 functions as an E3 ubiquitin ligase with, specific E2 ubiquitin-conjugating enzymes. The structure of the AtPUB14, U-box domain was determined by NMR spectroscopy. It adopts the, betabetaalphabeta fold of the Prp19p U-box and RING finger domains. In, these proteins, conserved hydrophobic residues form a putative E2-binding, cleft. By contrast, they contain no common polar E2 binding site motif., Two hydrophobic cores stabilize the AtPUB14 U-box fold, and hydrogen bonds, and salt bridges interconnect the residues corresponding to zinc, ion-coordinating residues in RING domains. Residues from a C-terminal, alpha-helix interact with the core domain and contribute to stabilization., The Prp19p U-box lacks a corresponding C-terminal alpha-helix. Chemical, shift analysis suggested that aromatic residues exposed at the N terminus, and the C-terminal alpha-helix of the AtPUB14 U-box participate in, dimerization. Thus, AtPUB14 may form a biologically relevant dimer. This, is the first plant U-box structure to be determined, and it provides a, model for studies of the many plant U-box proteins and their interactions., Structural insight into these interactions is important, because, ubiquitin-dependent protein degradation is a prevalent regulatory, mechanism in plants.
About this Structure
1T1H is a Single protein structure of sequence from Arabidopsis thaliana. Full crystallographic information is available from OCA.
Reference
Structure and biochemical function of a prototypical Arabidopsis U-box domain., Andersen P, Kragelund BB, Olsen AN, Larsen FH, Chua NH, Poulsen FM, Skriver K, J Biol Chem. 2004 Sep 17;279(38):40053-61. Epub 2004 Jun 30. PMID:15231834
Page seeded by OCA on Wed Nov 21 02:55:11 2007
