2hst
From Proteopedia
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Solution structure of the middle domain of human eukaryotic translation termination factor eRF1
Overview
The eukaryotic class 1 polypeptide chain release factor is a three-domain, protein involved in the termination of translation, the final stage of, polypeptide biosynthesis. In attempts to understand the roles of the, middle domain of the eukaryotic class 1 polypeptide chain release factor, in the transduction of the termination signal from the small to the large, ribosomal subunit and in peptidyl-tRNA hydrolysis, its high-resolution NMR, structure has been obtained. The overall fold and the structure of the, beta-strand core of the protein in solution are similar to those found in, the crystal. However, the orientation of the functionally critical GGQ, loop and neighboring alpha-helices has genuine and noticeable differences, in solution and in the crystal. Backbone amide protons of most of the, residues in the GGQ loop undergo fast exchange with water. However, in the, AGQ mutant, where functional activity is abolished, a significant, reduction in the exchange rate of the amide protons has been observed, without a noticeable change in the loop conformation, providing evidence, for the GGQ loop interaction with water molecule(s) that may serve as a, substrate for the hydrolytic cleavage of the peptidyl-tRNA in the, ribosome. The protein backbone dynamics, studied using (15)N relaxation, experiments, showed that the GGQ loop is the most flexible part of the, middle domain. The conformational flexibility of the GGQ and 215-223, loops, which are situated at opposite ends of the longest alpha-helix, could be a determinant of the functional activity of the eukaryotic class, 1 polypeptide chain release factor, with that helix acting as the trigger, to transmit the signals from one loop to the other.
About this Structure
2HST is a Single protein structure of sequence from Homo sapiens. Full crystallographic information is available from OCA.
Reference
Eukaryotic class 1 translation termination factor eRF1 - the NMR structure and dynamics of the middle domain involved in triggering ribosome-dependent peptidyl-tRNA hydrolysis., Ivanova EV, Kolosov PM, Birdsall B, Kelly G, Pastore A, Kisselev LL, Polshakov VI, FEBS J. 2007 Aug;274(16):4223-37. Epub 2007 Jul 25. PMID:17651434
Page seeded by OCA on Wed Jan 23 13:42:28 2008
