2ffw

From Proteopedia

proteopedia linkproteopedia link

spinqualitylabelsall models 2ffw Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image

Solution structure of the RBCC/TRIM B-box1 domain of human MID1: B-box with a RING

Contents 1 Overview 2 Disease 3 About this Structure 4 Reference

Overview

B-box domains are a defining feature of the tripartite RBCC (RING, B-box, coiled-coil) or TRIM proteins, many of which are E3 ubiquitin ligases., However, little is known about the biological function of B-boxes. In some, RBCC/TRIM proteins there is only a single B-box (type 2) domain, while, others have both type 1 and type 2 B-box domains in tandem adjacent to, their RING domain. These two types of B-boxes share little sequence, similarity, except the presence of cysteine and histidine residues: eight, in most B-box1 domains and seven in B-box2 domains. We report here the, high-resolution solution structure of the first B-box1 domain (from the, human RBCC protein, MID1) based on 670 nuclear Overhauser effect, (NOE)-derived distance restraints, 12 hydrogen bonds, and 44 dihedral, angles. The domain consists of a three-turn alpha-helix, two short, beta-strands, and three beta-turns, encompassing Val117 to Pro164, which, binds two zinc atoms. One zinc atom is coordinated by cysteine residues, 119, 122, 142, 145, while cysteine 134, 137 and histidine 150, 159, coordinate the other. This topology is markedly different from the only, other B-box structure reported; that of a type 2 B-box from Xenopus XNF7, which binds a single zinc atom. Of note, the B-box1 structure closely, resembles the folds of the RING, ZZ and U-box domains of E3 and E4, ubiquitin enzymes, raising the possibility that the B-box1 domain either, has E3 activity itself or enhances the activity of RING type E3 ligases, (i.e. confers E4 enzyme activity). The structure of the MID1 B-box1 also, reveals two potential protein interaction surfaces. One of these is likely, to provide the binding interface for Alpha 4 that is required for the, localized turnover of the catalytic subunit of PP2A, the major Ser/Thr, phosphatase.

Disease

Known diseases associated with this structure: Opitz G syndrome, type I OMIM:[300552]

About this Structure

2FFW is a Single protein structure of sequence from Homo sapiens with ZN as ligand. Full crystallographic information is available from OCA.

Reference

Solution structure of the RBCC/TRIM B-box1 domain of human MID1: B-box with a RING., Massiah MA, Simmons BN, Short KM, Cox TC, J Mol Biol. 2006 Apr 28;358(2):532-45. Epub 2006 Feb 20. PMID:16529770

Page seeded by OCA on Mon Nov 12 22:04:45 2007