1e7z

From Proteopedia

Revision as of 14:02, 5 November 2007

CRYSTAL STRUCTURE OF THE EMAP2/RNA BINDING DOMAIN OF THE P43 PROTEIN FROM HUMAN AMINOACYL-TRNA SYNTHETASE COMPLEX

Overview

The EMAPII (endothelial monocyte-activating polypeptide II) domain is a, tRNA-binding domain associated with several aminoacyl-tRNA synthetases, which becomes an independent domain with inflammatory cytokine activity, upon apoptotic cleavage from the p43 component of the multisynthetase, complex. It comprises a domain that is highly homologous to bacterial, tRNA-binding proteins (Trbp), followed by an extra domain without homology, to known proteins. Trbps, which may represent ancient tRNA chaperones, form dimers and bind one tRNA per dimer. In contrast, EMAPII domains are, monomers. Here we report the crystal structure at 1.14 Angstroms of human, EMAPII. The structure reveals that the Trbp-like domain, which forms an, oligonucleotide-binding (OB) fold, is related by degenerate 2-fold, symmetry to the extra-domain. The pseudo-axis coincides with the dyad axis, of bacterial TtCsaA, a Trbp whose structure was solved recently. The, interdomain interface in EMAPII mimics the intersubunit interface in, TtCsaA, and may thus generate a novel OB-fold-based tRNA-binding site. The, low sequence homology between the extra domain of EMAPII and either its, own OB fold or that of Trbps suggests that dimer mimicry originated from, convergent evolution rather than gene duplication.

About this Structure

1E7Z is a Single protein structure of sequence from Homo sapiens with HG as ligand. Structure known Active Sites: HG1 and HG2. Full crystallographic information is available from OCA.

Reference

Structure of the EMAPII domain of human aminoacyl-tRNA synthetase complex reveals evolutionary dimer mimicry., Renault L, Kerjan P, Pasqualato S, Menetrey J, Robinson JC, Kawaguchi S, Vassylyev DG, Yokoyama S, Mirande M, Cherfils J, EMBO J. 2001 Feb 1;20(3):570-8. PMID:11157763

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