1htt
From Proteopedia
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| , resolution 2.6Å | |||||||
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| Sites: | , , and | ||||||
| Ligands: | |||||||
| Activity: | Histidine--tRNA ligase, with EC number 6.1.1.21 | ||||||
| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
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. 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 Mar 30 21:10:19 2008
