2rbi

From Proteopedia

Revision as of 16:32, 5 November 2007

STRUCTURE OF BINASE MUTANT HIS 101 ASN

Overview

Members of the microbial guanyl-specific ribonuclease family catalyse the, endonucleolytic cleavage of single-stranded RNA in a two-step reaction, involving transesterification to form a 2',3'-cyclic phosphate and its, subsequent hydrolysis to yield the respective 3'-phosphate. The, extracellular ribonuclease from Bacillus intermedius (binase, RNase Bi), shares a common mechanism for RNA hydrolysis with mammalian RNases. Two, catalytic residues in the active site of binase, Glu72 and His101, are, thought to be involved in general acid-general base catalysis of RNA, cleavage. Using site-directed mutagenesis, binase mutants were produced, containing amino acid substitutions H101N and H101T and their catalytic, properties towards RNA, poly(I), poly(A), GpC and guanosine 2',3'-cyclic, phosphate (cGMP) substrates were studied. The engineered mutant proteins, are active in the transesterification step which produces the 2',3'-cyclic, phosphate species but they have lost the ability to catalyse hydrolysis of, the cyclic phosphate to give the 3' monophosphate product.

About this Structure

2RBI is a Single protein structure of sequence from Bacillus intermedius. Structure known Active Sites: 1, 2 and 3. Full crystallographic information is available from OCA.

Reference

RNA cleavage without hydrolysis. Splitting the catalytic activities of binase with Asn101 and Thr101 mutations., Okorokov AL, Panov KI, Offen WA, Mukhortov VG, Antson AA, Karpeisky MYa, Wilkinson AJ, Dodson GG, Protein Eng. 1997 Mar;10(3):273-8. PMID:9153077

Page seeded by OCA on Mon Nov 5 18:37:23 2007