1j7g
From Proteopedia
| Line 7: | Line 7: | ||
|ACTIVITY= | |ACTIVITY= | ||
|GENE= HI0670 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=727 Haemophilus influenzae]) | |GENE= HI0670 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=727 Haemophilus influenzae]) | ||
| + | |DOMAIN= | ||
| + | |RELATEDENTRY= | ||
| + | |RESOURCES=<span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1j7g FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1j7g OCA], [http://www.ebi.ac.uk/pdbsum/1j7g PDBsum], [http://www.rcsb.org/pdb/explore.do?structureId=1j7g RCSB]</span> | ||
}} | }} | ||
| Line 31: | Line 34: | ||
[[Category: structure 2 function project]] | [[Category: structure 2 function project]] | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun Mar 30 21:29:35 2008'' |
Revision as of 18:29, 30 March 2008
| |||||||
| , resolution 1.64Å | |||||||
|---|---|---|---|---|---|---|---|
| Gene: | HI0670 (Haemophilus influenzae) | ||||||
| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
Structure of YihZ from Haemophilus influenzae (HI0670), a D-Tyr-tRNA(Tyr) deacylase
Overview
D-Tyr-tRNA(Tyr) deacylase is an editing enzyme that removes d-tyrosine and other d-amino acids from charged tRNAs, thereby preventing incorrect incorporation of d-amino acids into proteins. A model for the catalytic mechanism of this enzyme is proposed based on the crystal structure of the enzyme from Haemophilus influenzae determined at a 1.64-A resolution. Structural comparison of this dimeric enzyme with the very similar structure of the enzyme from Escherichia coli together with sequence analyses indicate that the active site is located in the dimer interface within a depression that includes an invariant threonine residue, Thr-80. The active site contains an oxyanion hole formed by the main chain nitrogen atoms of Thr-80 and Phe-79 and the side chain amide group of the invariant Gln-78. The Michaelis complex between the enzyme and D-Tyr-tRNA was modeled assuming a nucleophilic attack on the carbonyl carbon of D-Tyr by the Thr-80 O(gamma) atom and a role for the oxyanion hole in stabilizing the negatively charged tetrahedral transition states. The model is consistent with all of the available data on substrate specificity. Based on this model, we propose a substrate-assisted acylation/deacylation-catalytic mechanism in which the amino group of the D-Tyr is deprotonated and serves as the general base.
About this Structure
1J7G is a Single protein structure of sequence from Haemophilus influenzae. Full crystallographic information is available from OCA.
Reference
A catalytic mechanism for D-Tyr-tRNATyr deacylase based on the crystal structure of Hemophilus influenzae HI0670., Lim K, Tempczyk A, Bonander N, Toedt J, Howard A, Eisenstein E, Herzberg O, J Biol Chem. 2003 Apr 11;278(15):13496-502. Epub 2003 Feb 4. PMID:12571243
Page seeded by OCA on Sun Mar 30 21:29:35 2008
