1gsg
From Proteopedia
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STRUCTURE OF E.COLI GLUTAMINYL-TRNA SYNTHETASE COMPLEXED WITH TRNAGLN AND ATP AT 2.8 ANGSTROMS RESOLUTION
Overview
The crystal structure of Escherichia coli glutaminyl-tRNA synthetase, (GlnRS) complexed with its cognate glutaminyl transfer RNA (tRNA(Gln] and, adenosine triphosphate (ATP) has been derived from a 2.8 angstrom, resolution electron density map and the known protein and tRNA sequences., The 63.4-kilodalton monomeric enzyme consists of four domains arranged to, give an elongated molecule with an axial ratio greater than 3 to 1. Its, interactions with the tRNA extend from the anticodon to the acceptor stem, along the entire inside of the L of the tRNA. The complexed tRNA retains, the overall conformation of the yeast phenylalanine tRNA (tRNA(Phe] with, two major differences: the 3' acceptor strand of tRNA(Gln) makes a hairpin, turn toward the inside of the L, with the disruption of the final base, pair of the acceptor stem, and the anticodon loop adopts a conformation, not seen in any of the previously determined tRNA structures. Specific, recognition elements identified so far include (i) enzyme contacts with, the 2-amino groups of guanine via the tRNA minor groove in the acceptor, stem at G2 and G3; (ii) interactions between the enzyme and the anticodon, nucleotides; and (iii) the ability of the nucleotides G73 and U1.A72 of, the cognate tRNA to assume a conformation stabilized by the protein at a, lower free energy cost than noncognate sequences. The central domain of, this synthetase binds ATP, glutamine, and the acceptor end of the tRNA as, well as making specific interactions with the acceptor stem.2+t is
About this Structure
1GSG is a Single protein structure of sequence from Escherichia coli. Active as Glutamine--tRNA ligase, with EC number 6.1.1.18 Full crystallographic information is available from OCA.
Reference
Structure of E. coli glutaminyl-tRNA synthetase complexed with tRNA(Gln) and ATP at 2.8 A resolution., Rould MA, Perona JJ, Soll D, Steitz TA, Science. 1989 Dec 1;246(4934):1135-42. PMID:2479982
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