Structural basis for Ni(2+) transport and assembly of the urease active site by the metallochaperone UreE from Bacillus pasteurii.

TitleStructural basis for Ni(2+) transport and assembly of the urease active site by the metallochaperone UreE from Bacillus pasteurii.
Publication TypeJournal Article
Year of Publication2001
AuthorsRemaut, H., N. Safarov, S. Ciurli, and J. Van Beeumen
JournalJ Biol Chem
Volume276
Issue52
Pagination49365-70
Date Published2001 Dec 28
ISSN0021-9258
KeywordsBacillus, Bacterial Proteins, Binding Sites, Carrier Proteins, Crystallography, X-Ray, Ion Transport, Models, Molecular, Molecular Chaperones, Nickel, Protein Conformation, Protein Structure, Quaternary, Urease, Zinc
Abstract

Bacillus pasteurii UreE (BpUreE) is a putative chaperone assisting the insertion of Ni(2+) ions in the active site of urease. The x-ray structure of the protein has been determined for two crystal forms, at 1.7 and 1.85 A resolution, using SIRAS phases derived from a Hg(2+)-derivative. BpUreE is composed of distinct N- and C-terminal domains, connected by a short flexible linker. The structure reveals the topology of an elongated homodimer, formed by interaction of the two C-terminal domains through hydrophobic interactions. A single Zn(2+) ion bound to four conserved His-100 residues, one from each monomer, connects two dimers resulting in a tetrameric BpUreE known to be formed in concentrated solutions. The Zn(2+) ion can be replaced by Ni(2+) as shown by anomalous difference maps obtained on a crystal of BpUreE soaked in a solution containing NiCl(2). A large hydrophobic patch surrounding the metal ion site is surface-exposed in the biologically relevant dimer. The BpUreE structure represents the first for this class of proteins and suggests a possible role for UreE in the urease nickel-center assembly.

DOI10.1074/jbc.M108304200
Alternate JournalJ. Biol. Chem.
PubMed ID11602602