2pth: Difference between revisions

[[Image:2pth.jpg|left|200px]]<br /><applet load="2pth" size="350" color="white" frame="true" align="right" spinBox="true"  

Peptidyl-tRNA hydrolase activity from Escherichia coli ensures the recycling of peptidyl-tRNAs produced through abortion of translation. This activity, which is essential for cell viability, is carried out by a monomeric protein of 193 residues. The structure of crystalline peptidyl-tRNA hydrolase could be solved at 1.2 A resolution. It indicates a single alpha/beta globular domain built around a twisted mixed beta-sheet, similar to the central core of an aminopeptidase from Aeromonas proteolytica. This similarity allowed the characterization by site-directed mutagenesis of several residues of the active site of peptidyl-tRNA hydrolase. These residues, strictly conserved among the known peptidyl-tRNA hydrolase sequences, delineate a channel which, in the crystal, is occupied by the C-end of a neighbouring peptidyl-tRNA hydrolase molecule. Hence, several main chain atoms of three residues belonging to one peptidyl-tRNA hydrolase polypeptide establish contacts inside the active site of another peptidyl-tRNA hydrolase molecule. Such an interaction is assumed to represent the formation of a complex between the enzyme and one product of the catalysed reaction.

2PTH is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. Active as [http://en.wikipedia.org/wiki/Aminoacyl-tRNA_hydrolase Aminoacyl-tRNA hydrolase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.1.1.29 3.1.1.29] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2PTH OCA].  

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