1nzj
From Proteopedia
Crystal Structure and Activity Studies of Escherichia Coli Yadb ORF
Structural highlights
Function[GLUQ_ECOLI] Catalyzes the tRNA-independent activation of glutamate in presence of ATP and the subsequent transfer of glutamate onto tRNA(Asp). Glutamate is transferred on the 2-amino-5-(4,5-dihydroxy-2-cyclopenten-1-yl) moiety of the queuosine in position 34 of the tRNA(Asp), the wobble position of the QUC anticodon. Does not transfer glutamate to either tRNA(Glu) or tRNA(Gln). The incapacity of the glutamylated tRNA(Asp) to bind elongation factor Tu suggests that it is not involved in ribosomal protein biosynthesis.[1] [2] [3] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedIn the course of a structural genomics program aiming at solving the structures of Escherichia coli open reading frame products of unknown function, we have determined the structure of YadB at 1.5A using molecular replacement. The YadB protein is 298 amino acid residues long and displays 34% sequence identity with E.coli glutamyl-tRNA synthetase (GluRS). It is much shorter than GluRS, which contains 468 residues, and lacks the complete domain interacting with the tRNA anticodon loop. As E.coli GluRS, YadB possesses a Zn2+ located in the putative tRNA acceptor stem-binding domain. The YadB cluster uses cysteine residues as the first three zinc ligands, but has a weaker tyrosine ligand at the fourth position. It shares with canonical amino acid RNA synthetases a major functional feature, namely activation of the amino acid (here glutamate). It differs, however, from GluRSs by the fact that the activation step is tRNA-independent and that it does not catalyze attachment of the activated glutamate to E.coli tRNAGlu, but to another, as yet unknown tRNA. These results suggest thus a novel function, distinct from that of GluRSs, for the yadB gene family. The Escherichia coli YadB gene product reveals a novel aminoacyl-tRNA synthetase like activity.,Campanacci V, Dubois DY, Becker HD, Kern D, Spinelli S, Valencia C, Pagot F, Salomoni A, Grisel S, Vincentelli R, Bignon C, Lapointe J, Giege R, Cambillau C J Mol Biol. 2004 Mar 19;337(2):273-83. PMID:15003446[4] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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