This old version of Proteopedia is provided for student assignments while the new version is undergoing repairs. Content and edits done in this old version of Proteopedia after March 1, 2026 will eventually be lost when it is retired in about June of 2026.
Apply for new accounts at the new Proteopedia. Your logins will work in both the old and new versions.
1fyf
From Proteopedia
|
CRYSTAL STRUCTURE OF A TRUNCATED FORM OF THREONYL-TRNA SYNTHETASE COMPLEXED WITH A SERYL ADENYLATE ANALOG
Overview
Threonyl-tRNA synthetase, a class II synthetase, uses a unique zinc ion to, discriminate against the isosteric valine at the activation step. The, crystal structure of the enzyme with an analog of seryl adenylate shows, that the noncognate serine cannot be fully discriminated at that step. We, show that hydrolysis of the incorrectly formed ser-tRNA(Thr) is performed, at a specific site in the N-terminal domain of the enzyme. The present, study suggests that both classes of synthetases use effectively the, ability of the CCA end of tRNA to switch between a hairpin and a helical, conformation for aminoacylation and editing. As a consequence, the editing, mechanism of both classes of synthetases can be described as mirror, images, as already seen for tRNA binding and amino acid activation.
About this Structure
1FYF is a Single protein structure of sequence from Escherichia coli with ZN and SSA as ligands. Active as Threonine--tRNA ligase, with EC number 6.1.1.3 Full crystallographic information is available from OCA.
Reference
Transfer RNA-mediated editing in threonyl-tRNA synthetase. The class II solution to the double discrimination problem., Dock-Bregeon A, Sankaranarayanan R, Romby P, Caillet J, Springer M, Rees B, Francklyn CS, Ehresmann C, Moras D, Cell. 2000 Dec 8;103(6):877-84. PMID:11136973
Page seeded by OCA on Tue Nov 20 15:28:11 2007
