1htt
From Proteopedia
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==Overview== | ==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, | + | 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== | ==About this Structure== | ||
| - | 1HTT is a | + | 1HTT is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli] with AMP as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [http://en.wikipedia.org/wiki/Histidine--tRNA_ligase Histidine--tRNA ligase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=6.1.1.21 6.1.1.21] Structure known Active Sites: S1A, S1B, S1C and S1D. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1HTT OCA]. |
==Reference== | ==Reference== | ||
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[[Category: synthetase]] | [[Category: synthetase]] | ||
| - | ''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on | + | ''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Mon Nov 5 12:30:26 2007'' |
Revision as of 10:25, 5 November 2007
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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 AMP as ligand. Active as Histidine--tRNA ligase, with EC number 6.1.1.21 Structure known Active Sites: S1A, S1B, S1C and S1D. 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
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