1udn
From Proteopedia
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Crystal structure of the tRNA processing enzyme RNase PH from Aquifex aeolicus
Overview
RNase PH is one of the exoribonucleases that catalyze the 3' end processing of tRNA in bacteria. RNase PH removes nucleotides following the CCA sequence of tRNA precursors by phosphorolysis and generates mature tRNAs with amino acid acceptor activity. In this study, we determined the crystal structure of Aquifex aeolicus RNase PH bound with a phosphate, a co-substrate, in the active site at 2.3-A resolution. RNase PH has the typical alpha/beta fold, which forms a hexameric ring structure as a trimer of dimers. This ring structure resembles that of the polynucleotide phosphorylase core domain homotrimer, another phosphorolytic exoribonuclease. Four amino acid residues, Arg-86, Gly-124, Thr-125, and Arg-126, of RNase PH are involved in the phosphate-binding site. Mutational analyses of these residues showed their importance in the phosphorolysis reaction. A docking model with the tRNA acceptor stem suggests how RNase PH accommodates substrate RNAs.
About this Structure
1UDN is a Single protein structure of sequence from Aquifex aeolicus with and as ligands. Active as tRNA nucleotidyltransferase, with EC number 2.7.7.56 Full crystallographic information is available from OCA.
Reference
Crystal structure of the tRNA processing enzyme RNase PH from Aquifex aeolicus., Ishii R, Nureki O, Yokoyama S, J Biol Chem. 2003 Aug 22;278(34):32397-404. Epub 2003 May 12. PMID:12746447
Page seeded by OCA on Thu Feb 21 15:23:23 2008
