Gene fusions with β‐lactamase show that subunit I of the cytochrome bd quinol oxidase from E. coli has nine transmembrane helices with the O2 reactive site near the periplasmic surface

FEBS Letters

Barquera, Blanca¹  Gennis, Robert B¹  Zhang, Jie¹ 

[1] Department of Biochemistry, University of Illinois, 600 South Mathews Street, Urbana, IL 61801, USA

关键词: Oxidase;    Cytochrome bd;    Topology;    Membrane protein;    β-Lactamase;    Gene fusion;   

DOI  :  10.1016/S0014-5793(04)00125-5

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The cytochrome bd quinol oxidase is a component of the respiratory chain of many prokaryotes. The enzyme contains two subunits, CydA and CydB, which were initially predicted based on the sequence of the Escherichia coli oxidase to have seven and eight transmembrane spans, respectively. More recently, the topological model of CydA was revised to predict nine transmembrane helices, based on additional sequence information from other organisms. In the current work, the topology of the E. coli oxidase was experimentally examined using β-lactamase gene fusions. The results confirm the revised topology, which places the oxygen reactive site near the periplasmic surface.

【 授权许可】

Unknown