2ayi
From Proteopedia
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Wild-type AmpT from Thermus thermophilus
Overview
Aminopeptidase T (AmpT) from Thermus thermophilus is a metalloexopeptidase, with no similarity to prototypical metallopeptidases with an HExxH or, HxxEH motif. The crystal structure of the Staphylococcus aureus homologue, of AmpT, which is known as aminopeptidase S (AmpS), has been reported, recently. This structure revealed a dimeric protein with a very unusual, elongated shape and a large internal cavity. The active sites were found, on the inner walls of the cavity and were entirely shielded from the, environment, which suggested either that the dimer in the crystals was not, physiologically relevant, or that an inactive conformation had been, crystallized. Here, we show by gel-filtration and analytical, ultracentrifugation that AmpT, like AmpS, forms dimers in solution, and we, present the structure of AmpT in a crystal form with five protomers in the, asymmetric unit. The five protomers take conformations that range from, fully closed, as in the AmpS structure, to nearly open, so that the active, site is almost directly accessible. The different conformations indicate, flexibility between the AmpT N and C-domains, and explain how AmpT can be, active, although the unusual AmpS dimerization mode applies to AmpT as, well.
About this Structure
2AYI is a Single protein structure of sequence from Thermus thermophilus with ZN as ligand. Full crystallographic information is available from OCA.
Reference
Substrate access to the active sites in aminopeptidase T, a representative of a new metallopeptidase clan., Odintsov SG, Sabala I, Bourenkov G, Rybin V, Bochtler M, J Mol Biol. 2005 Nov 25;354(2):403-12. Epub 2005 Sep 30. PMID:16242715
Page seeded by OCA on Wed Nov 21 08:27:44 2007
