1pv9
Prolidase from Pyrococcus furiosus
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OverviewOverview
The structure of prolidase from the hyperthermophilic archaeon Pyrococcus, furiosus (Pfprol) has been solved and refined at 2.0 A resolution. This is, the first structure of a prolidase, i.e., a peptidase specific for, dipeptides having proline as the second residue. The asymmetric unit of, the crystals contains a homodimer of the enzyme. Each of the two protein, subunits has two domains. The C-terminal domain includes the catalytic, site, which is centered on a dinuclear metal cluster. In the as-isolated, form of Pfprol, the active-site metal atoms are Co(II) [Ghosh, M., et al., (1998) J. Bacteriol. 180, 4781-9]. An unexpected finding is that in the, crystalline enzyme the active-site metal atoms are Zn(II), presumably as a, result of metal exchange during crystallization. Both of the Zn(II) atoms, are five-coordinate. The ligands include a bridging water molecule or, hydroxide ion, which is likely to act as a nucleophile in the catalytic, reaction. The two-domain polypeptide fold of Pfprol is similar to the, folds of two functionally related enzymes, aminopeptidase P (APPro) and, creatinase. In addition, the catalytic C-terminal domain of Pfprol has a, polypeptide fold resembling that of the sole domain of a fourth enzyme, methionine aminopeptidase (MetAP). The active sites of APPro and MetAP, like that of Pfprol, include a dinuclear metal center. The metal ligands, in the three enzymes are homologous. Comparisons with the molecular, structures of APPro and MetAP suggest how Pfprol discriminates against, oligopeptides and in favor of Xaa-Pro substrates. The crystal structure of, Pfprol was solved by multiple-wavelength anomalous dispersion. The, crystals yielded diffraction data of relatively high quality and, resolution, despite the fact that one of the two protein subunits in the, asymmetric unit was found to be significantly disordered. The final R and, R(free) values are 0.24 and 0.28, respectively.
About this StructureAbout this Structure
1PV9 is a Single protein structure of sequence from Pyrococcus furiosus with ZN as ligand. Active as Xaa-Pro dipeptidase, with EC number 3.4.13.9 Full crystallographic information is available from OCA.
ReferenceReference
Structure of the prolidase from Pyrococcus furiosus., Maher MJ, Ghosh M, Grunden AM, Menon AL, Adams MW, Freeman HC, Guss JM, Biochemistry. 2004 Mar 16;43(10):2771-83. PMID:15005612
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