1fwi
From Proteopedia
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KLEBSIELLA AEROGENES UREASE, H134A VARIANT
Overview
A mutant form of Klebsiella aerogenes urease possessing Ala instead of His, at position 134 (H134A) is inactive and binds approximately half the, normal complement of nickel (Park, I.-S., and Hausinger, R. P.(1993), Protein Sci. 2, 1034-1041). The crystal structure of the H134A protein was, obtained at 2.0-A resolution, and it confirms that only Ni-1 of the two, nickel ions found in the native enzyme is present. In contrast to the, pseudotetrahedral geometry observed for Ni-1 in native urease (where it is, liganded by His-246, His-272, one oxygen atom of carbamylated Lys-217, and, a water molecule at partial occupancy), the mononickel metallocenter in, the H134A protein was found to possess octahedral geometry and was, coordinated by the above protein ligands plus three water molecules. The, nickel site of H134A urease was probed by UV-visible, variable temperature, magnetic circular dichroism, and x-ray absorption spectroscopies. The, spectroscopic data are consistent with the presence of Ni(II) in, octahedral geometry coordinated by two histidylimidazoles and additional, oxygen and/or nitrogen donors. These data underscore the requirement of, Ni-2 for formation of active urease and demonstrate the important role of, Ni-2 in establishing the proper Ni-1 coordination geometry.
About this Structure
1FWI is a Protein complex structure of sequences from Klebsiella aerogenes with NI as ligand. Active as Urease, with EC number 3.5.1.5 Known structural/functional Sites: and . Full crystallographic information is available from OCA.
Reference
Characterization of the mononickel metallocenter in H134A mutant urease., Park IS, Michel LO, Pearson MA, Jabri E, Karplus PA, Wang S, Dong J, Scott RA, Koehler BP, Johnson MK, Hausinger RP, J Biol Chem. 1996 Aug 2;271(31):18632-7. PMID:8702515
Page seeded by OCA on Tue Dec 18 15:18:24 2007
