Open AccessRespiratory pathways of Rhodobacter sphaeroides 2.4.1 T : identification and characterization of genes encoding quinol oxidases
Author(s) -
Mouncey Nigel J,
Gak Evgueni,
Choudhary Madhu,
Oh JeongIl,
Kaplan Samuel
Publication year - 2000
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.2000.tb09383.x
Subject(s) - rhodobacter sphaeroides , identification (biology) , gene , rhodospirillaceae , biology , chemistry , genetics , computational biology , bacteria , botany
Rhodobacter sphaeroides 2.4.1 T respires aerobically via a branched respiratory chain consisting of both cytochrome c oxidases and quinol oxidases. Here, genes from chromosome II encoding two distinct quinol oxidases have been characterized. The qoxBA genes encode a putative heme‐copper quinol oxidase, whereas the qxtAB genes encode a quinol oxidase homologous to the cyanide‐insensitive oxidase of Pseudomonas aeruginosa . No phenotype was observed for mutations in either oxidase in the wild‐type background. A strain containing a qxtA mutation in a cytochrome bc 1 complex mutant background was unable to grow aerobically. No role was found for the Qox oxidase, nor was a qoxB :: lacZ transcriptional fusion expressed under a variety of conditions. These are the first molecular studies to characterize the quinol oxidases of R. sphaeroides 2.4.1 T .