1htt
From Proteopedia
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HISTIDYL-TRNA SYNTHETASE
Overview
The crystal structure at 2.6 A of the histidyl-tRNA synthetase from, Escherichia coli complexed with histidyl-adenylate has been determined., The enzyme is a homodimer with a molecular weight of 94 kDa and belongs to, the class II of aminoacyl-tRNA synthetases (aaRS). The asymmetric unit is, composed of two homodimers. Each monomer consists of two domains. The, N-terminal catalytic core domain contains a six-stranded antiparallel, beta-sheet sitting on two alpha-helices, which can be superposed with the, catalytic domains of yeast AspRS, and GlyRS and SerRS from Thermus, thermophilus with a root-mean-square difference on the C alpha atoms of, 1.7-1.9 A. The active sites of all four monomers are occupied by, histidyl-adenylate, which apparently forms during crystallization. The 100, residue C-terminal alpha/beta domain resembles half of a beta-barrel, and, provides an independent domain oriented to contact the anticodon stem and, part of the anticodon loop of tRNA(His). The modular domain organization, of histidyl-tRNA synthetase reiterates a repeated theme in aaRS, and its, structure should provide insight into the ability of certain aaRS to, aminoacylate minihelices and other non-tRNA molecules.
About this Structure
1HTT is a Single protein structure of sequence from Escherichia coli with as ligand. Active as Histidine--tRNA ligase, with EC number 6.1.1.21 Known structural/functional Sites: , , and . Full crystallographic information is available from OCA.
Reference
Crystal structure of histidyl-tRNA synthetase from Escherichia coli complexed with histidyl-adenylate., Arnez JG, Harris DC, Mitschler A, Rees B, Francklyn CS, Moras D, EMBO J. 1995 Sep 1;14(17):4143-55. PMID:7556055
Page seeded by OCA on Sun Feb 3 09:50:16 2008
