1pvv
From Proteopedia
Refined Structure of Pyrococcus furiosus Ornithine Carbamoyltransferase at 1.87 A
Overview
Using synchrotron radiation, X-ray data have been collected from Pyrococcus furiosus ornithine carbamoyltransferase (Pfu OTCase) to a maximal resolution of 1.87 A, allowing the refinement of a previous structure at 2.7 A [Villeret et al. (1998), Proc. Natl Acad. Sci. USA, 95, 2801-2806]. Thanks to the high resolution of this refined structure, two sulfate ions and 191 water molecules could be localized directly from the electron-density maps. The identification of these molecules allowed a more rigorous description of the active site and the identification of residues involved in binding carbamoyl phosphate. The improved quality of the model resulted in a better definition of several loops and the various interfaces. The dodecameric protein is composed of four catalytic trimers disposed in a tetrahedral manner. The extreme thermal stability of Pfu OTCase is mainly the result of the strengthening of the intersubunit interactions in a trimer and oligomerization of the trimers into a dodecamer. Interfaces between monomers in a catalytic trimer are characterized by an increase in ion-pair networks compared with mesophilic OTCases. However, the interfaces between catalytic trimers in the dodecameric oligomer are mainly hydrophobic and also involve aromatic-aromatic and cation-pi interactions.
About this Structure
1PVV is a Single protein structure of sequence from Pyrococcus furiosus. Full crystallographic information is available from OCA.
Reference
Refined structure of Pyrococcus furiosus ornithine carbamoyltransferase at 1.87 A., Massant J, Wouters J, Glansdorff N, Acta Crystallogr D Biol Crystallogr. 2003 Dec;59(Pt 12):2140-9. Epub 2003, Nov 27. PMID:14646072 Page seeded by OCA on Sat May 3 05:32:47 2008
