Biochemical pathway for the biosynthesis of the Cu A center in bacterial cytochrome c oxidase

FEBS Letters

article

Fabia Canonica¹  Hauke Hennecke²  Rudi Glockshuber¹ 

[1] Institute of Molecular Biology and Biophysics;Institute of Microbiology

关键词: Alpha-Proteobacteria;    cofactor biosynthesis;    copper A center;    copper trafficking;    cytochrome oxidase;    disulfide reductase;    membrane protein;    metallochaperones;    mitochondria;    periplasm;   

DOI  :  10.1002/1873-3468.13587

来源: John Wiley & Sons Ltd.

【 摘 要 】

The di-copper center CuA is an essential metal cofactor in cytochrome oxidase (Cox) of mitochondria and many prokaryotes, mediating one-electron transfer from cytochrome c to the site for oxygen reduction. CuA is located in subunit II (CoxB) of Cox and protrudes into the periplasm of Gram-negative bacteria or the mitochondrial intermembrane space. How the two copper ions are brought together to build CoxB·CuA is the subject of this review. It had been known that the reductase TlpA and the metallochaperones ScoI and PcuC are required for CuA formation in bacteria, but the mechanism of copper transfer has emerged only recently for the Bradyrhizobium diazoefficiens system. It consists of the following steps: (a) TlpA keeps the active site cysteine pair of CoxB in its dithiol state as a prerequisite for metal insertion; (b) ScoI·Cu2+ rapidly forms a transient complex with apo-CoxB; (c) PcuC, loaded with Cu1+ and Cu2+ , dissociates this complex to CoxB·Cu2+ , and a second PcuC·Cu1+ ·Cu2+ transfers Cu1+ to CoxB·Cu2+ , yielding mature CoxB·CuA. Variants of this pathway might exist in other bacteria or mitochondria.

【 授权许可】

Unknown