Open AccessExpression Studies on the ba 3 Quinol Oxidase from Paracoccus Denitrificans A bb 3 Variant is Enzymatically Inactive
Author(s) -
Zickermann Irmela,
Tautu Oltea S.,
Link Thomas A.,
Korn Marcus,
Ludwig Bernd,
Richter OliverMatthias H.
Publication year - 1997
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1997.00618.x
Subject(s) - paracoccus denitrificans , cytochrome c oxidase , oxidase test , operon , heme a , heme , chemistry , biochemistry , cytochrome , electron transport complex iv , nitrite reductase , microbiology and biotechnology , biology , enzyme , gene , nitrate reductase , escherichia coli
Expression of the quinol oxidase from Paracoccus denitrificans has been examined using a polyclonal antibody directed against subunit II and a promoter probe vector carrying the promoter region of the qox operon. Under aerobic conditions nitrate and nitrite act as specific inducers of the expression. To obtain an enzymatically competent quinol oxidase complex, an intact cta B gene is required, which constitutes part of the cta operon coding for the aa 3 cytochrome c oxidase of P. denitrificans. Deletion of cta B leads to a change in heme composition of the quinol oxidase with heme b replacing the high‐spin heme a of the binuclear center, causing loss of electron transport activity.