Nickel-binding properties of the C-terminal tail peptide of Bacillus pasteurii UreE.
Urease activation, which is critical to the virulence of many human and animal pathogens, is mediated by several accessory proteins. UreE, the only nickel-binding protein among the urease accessory proteins, catalyzes the activation of urease by transporting nickel ions into the urease active sites. The nickel-binding properties of UreE are still not clear, particularly for the protein from Bacillus pasteurii (Bp). Since the flexible C-terminal tail of BpUreE possesses two conserved histidines, the nickel-binding properties of the tail peptide were examined by circular dichroism spectroscopy, size-exclusion chromatography, and nuclear magnetic resonance spectroscopy. Specific nickel binding leading to alteration of the peptide backbone geometry was clearly observed. Side-chains of the two conserved histidines were identified as the main ligands for nickel coordination. The peptide became dimerized upon nickel binding and the binding stoichiometry was estimated as 1 equivalent of nickel per peptide dimer. Altogether, it is postulated that the C-terminal tail of BpUreE contributes to the nickel binding of the protein in different ways between the dimeric and tetrameric protein folds.
Won
Hyung-Sik
HS
National Research Laboratory (MPS), Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University, San 56-1, Shillim-Dong, Kwanak-Gu, Seoul 151-742, South Korea.
Lee
Bong-Jin
BJ
D001407:Bacillus / Q000737:chemistry*; D001426:Bacterial Proteins / Q000737:chemistry*; D002352:Carrier Proteins / Q000737:chemistry*; D002384:Catalysis; D002850:Chromatography, Gel / Q000379:methods; D002942:Circular Dichroism; D009682:Magnetic Resonance Spectroscopy; D009532:Nickel / Q000737:chemistry*; D010455:Peptides / Q000737:chemistry*; D017434:Protein Structure, Tertiary; D014510:Urease / Q000737:chemistry
D001426:Bacterial Proteins; D002352:Carrier Proteins; D010455:Peptides; C090404:UreE protein, Bacteria; D009532:Nickel; D014510:Urease