1udq: Difference between revisions

[[Image:1udq.jpg|left|200px]]<br /><applet load="1udq" size="350" color="white" frame="true" align="right" spinBox="true"  

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.

1UDQ is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Aquifex_aeolicus Aquifex aeolicus] with <scene name='pdbligand=PO4:'>PO4</scene> and <scene name='pdbligand=SO4:'>SO4</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/tRNA_nucleotidyltransferase tRNA nucleotidyltransferase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.7.7.56 2.7.7.56] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1UDQ OCA].  

[[Category: RSGI, RIKEN Structural Genomics/Proteomics Initiative.]]

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