1rls
From Proteopedia
OCA (Talk | contribs)
(New page: 200px<br /><applet load="1rls" size="450" color="white" frame="true" align="right" spinBox="true" caption="1rls, resolution 1.9Å" /> '''CRYSTAL STRUCTURE OF ...)
Next diff →
Revision as of 23:34, 20 November 2007
|
CRYSTAL STRUCTURE OF RNASE T1 COMPLEXED WITH THE PRODUCT NUCLEOTIDE 3'-GMP. STRUCTURAL EVIDENCE FOR DIRECT INTERACTION OF HISTIDINE 40 AND GLUTAMIC ACID 58 WITH THE 2'-HYDROXYL GROUP OF RIBOSE
Overview
The crystal structure of RNase T1 complexed with 3'-GMP has been, determined. The glycosyl conformation of 3'-GMP is in the syn, conformation, and the ribose adopts the O4'-endo pucker. This observed, pucker is different from that in any complex structures of RNase T1. In, the present complex, this energetically unfavorable conformation is, stabilized by the water molecule with the bridged hydrogen bonds between, the O2' and the O3' atoms of the ribose. The guanine base is recognized in, the same manner as observed in the complex of 2'-GMP. The 2'-hydroxyl, group of the ribose shows a tight hydrogen bond to both His-40 and Glu-58, with the suitable geometry for the proton transfer. These hydrogen bonds, suggest that the two residues can participate directly in the proton, transfer. His-92 is hydrogen bonded to two the proton transfer. His-92 is, hydrogen bonded to two oxygen atoms of the phosphate group. Based on the, geometry in the active site, the O1P atom may correspond to the O5' atom, of the leaving nucleotide in the phosphoryl transfer or a water molecule, as a nucleophile in the hydrolysis reaction. In the present complex, the, conformations of the 3'-GMP molecule and the side chains of the catalytic, residues would be represented as the conformation before the phosphoryl, transfer reaction and/or after the hydrolysis reaction.
About this Structure
1RLS is a Single protein structure of sequence from Aspergillus oryzae with CA and 3GP as ligands. Active as Ribonuclease T(1), with EC number 3.1.27.3 Full crystallographic information is available from OCA.
Reference
Crystal structure of RNase T1 complexed with the product nucleotide 3'-GMP. Structural evidence for direct interaction of histidine 40 and glutamic acid 58 with the 2'-hydroxyl group of the ribose., Gohda K, Oka K, Tomita K, Hakoshima T, J Biol Chem. 1994 Jul 1;269(26):17531-6. PMID:7912696
Page seeded by OCA on Wed Nov 21 01:41:51 2007
