Crystal Structures of Apo and Metal-Bound Forms of the UreE Protein from Helicobacter pylori: Role of Multiple Metal Binding Sites,

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• 作者：Rong Shi ; Christine Munger ; Abdalin Asinas ; Stphane L. Benoit ; Erica Miller ; Allan Matte ; Robert J. Maier ; Miroslaw Cygler
• 刊名：Biochemistry
• 出版年：2010
• 出版时间：August 24, 2010
• 年：2010
• 卷：49
• 期：33
• 页码：7080-7088
• 全文大小：1031K
• 年卷期：v.49,no.33(August 24, 2010)
• ISSN：1520-4995

文摘

The crystal structure of the urease maturation protein UreE from Helicobacter pylori has been determined in its apo form at 2.1 Å resolution, bound to Cu²⁺ at 2.7 Å resolution, and bound to Ni²⁺ at 3.1 Å resolution. Apo UreE forms dimers, while the metal-bound enzymes are arranged as tetramers that consist of a dimer of dimers associated around the metal ion through coordination by His102 residues from each subunit of the tetramer. Comparison of independent subunits from different crystal forms indicates changes in the relative arrangement of the N- and C-terminal domains in response to metal binding. The improved ability of engineered versions of UreE containing hexahistidine sequences at either the N-terminal or C-terminal end to provide Ni²⁺ for the final metal sink (urease) is eliminated in the H102A version. Therefore, the ability of the improved Ni²⁺-binding versions to deliver more nickel is likely an effect of an increased local concentration of metal ions that can rapidly replenish transferred ions bound to His102.