1kmn

From Proteopedia

HISTIDYL-TRNA SYNTHETASE COMPLEXED WITH HISTIDINOL AND ATP

PDB ID 1kmn

Drag the structure with the mouse to rotate

Structural highlights

1kmn is a 4 chain structure with sequence from Escherichia coli. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:	X-ray diffraction, Resolution 2.8Å
Ligands:	,
Resources:	FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

SYH_ECOLI

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 PubMed

The crystal structure of an enzyme-substrate complex with histidyl-tRNA synthetase from Escherichia coli, ATP, and the amino acid analog histidinol is described and compared with the previously obtained enzyme-product complex with histidyl-adenylate. An active site arginine, Arg-259, unique to all histidyl-tRNA synthetases, plays the role of the catalytic magnesium ion seen in seryl-tRNA synthetase. When Arg-259 is substituted with histidine, the apparent second order rate constant (kcat/Km) for the pyrophosphate exchange reaction and the aminoacylation reaction decreases 1,000-fold and 500-fold, respectively. Crystals soaked with MnCl2 reveal the existence of two metal binding sites between beta- and gamma-phosphates; these sites appear to stabilize the conformation of the pyrophosphate. The use of both conserved metal ions and arginine in phosphoryl transfer provides evidence of significant early functional divergence of class II aminoacyl-tRNA synthetases.

The first step of aminoacylation at the atomic level in histidyl-tRNA synthetase.,Arnez JG, Augustine JG, Moras D, Francklyn CS Proc Natl Acad Sci U S A. 1997 Jul 8;94(14):7144-9. PMID:9207058^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

References

↑ Arnez JG, Augustine JG, Moras D, Francklyn CS. The first step of aminoacylation at the atomic level in histidyl-tRNA synthetase. Proc Natl Acad Sci U S A. 1997 Jul 8;94(14):7144-9. PMID:9207058