2hz7
Crystal structure of the Glutaminyl-tRNA synthetase from Deinococcus radiodurans
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OverviewOverview
Glutaminyl-tRNA synthetase from Deinococcus radiodurans possesses a, C-terminal extension of 215 residues appending the anticodon-binding, domain. This domain constitutes a paralog of the Yqey protein present in, various organisms and part of it is present in the C-terminal end of the, GatB subunit of GatCAB, a partner of the indirect pathway of Gln-tRNA(Gln), formation. To analyze the peculiarities of the structure-function, relationship of this GlnRS related to the Yqey domain, a structure of the, protein was solved from crystals diffracting at 2.3 A and a docking model, of the synthetase complexed to tRNA(Gln) constructed. The comparison of, the modeled complex with the structure of the E. coli complex reveals that, all residues of E. coli GlnRS contacting tRNA(Gln) are conserved in D., radiodurans GlnRS, leaving the functional role of the Yqey domain, puzzling. Kinetic investigations and tRNA-binding experiments of full, length and Yqey-truncated GlnRSs reveal that the Yqey domain is involved, in tRNA(Gln) recognition. They demonstrate that Yqey plays the role of an, affinity-enhancer of GlnRS for tRNA(Gln) acting only in cis. However, the, presence of Yqey in free state in organisms lacking GlnRS, suggests that, this domain may exert additional cellular functions.
About this StructureAbout this Structure
2HZ7 is a Single protein structure of sequence from Deinococcus radiodurans. Active as Glutamine--tRNA ligase, with EC number 6.1.1.18 Full crystallographic information is available from OCA.
ReferenceReference
Deinococcus glutaminyl-tRNA synthetase is a chimer between proteins from an ancient and the modern pathways of aminoacyl-tRNA formation., Deniziak M, Sauter C, Becker HD, Paulus CA, Giege R, Kern D, Nucleic Acids Res. 2007;35(5):1421-31. Epub 2007 Feb 6. PMID:17284460
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