Oxygen Reductases in Alphaproteobacterial Genomes: Physiological Evolution From Low to High Oxygen Environments.

ABSTRACT: Oxygen reducing terminal oxidases differ with respect to their subunit composition, heme groups, operon structure, and affinity for O₂. Six families of terminal oxidases are currently recognized, all of which occur in alphaproteobacterial genomes, two of which are also present in mitochondria. Many alphaproteobacteria encode several different terminal oxidases, likely reflecting ecological versatility with respect to oxygen levels. Terminal oxidase evolution likely started with the advent of O₂ roughly 2.4 billion years ago and terminal oxidases diversified in the Proterozoic, during which oxygen levels remained low, around the Pasteur point (ca. 2 μM O₂). Among the alphaproteobacterial genomes surveyed, those from members of the Rhodospirillaceae reveal th

SUBMITTER: Degli Esposti M 

PROVIDER: S-EPMC6431628 | biostudies-literature | 2019

REPOSITORIES: biostudies-literature