Biogenesis of cbb3-type cytochrome c oxidase in Rhodobacter capsulatus

Abstract

The cbb3-type cytochrome c oxidases (cbb3-Cox) constitute the second most abundant cytochrome c oxidase (Cox) group after the mitochondrial-like aa3-type Cox. They are present in bacteria only, and are considered to represent a primordial innovation in the domain of Eubacteria due to their phylogenetic distribution and their similarity to nitric oxide (NO) reductases. They are crucial for the onset of many anaerobic biological processes, such as anoxygenic photosynthesis or nitrogen fixation. In addition, they are prevalent in many pathogenic bacteria, and important for colonizing low oxygen tissues. Studies related to cbb3-Cox provide a fascinating paradigm for the biogenesis of sophisticated oligomeric membrane proteins. Complex subunit maturation and assembly machineries, producing the c-type cytochromes and the binuclear heme b3-CuB center, have to be coordinated precisely both temporally and spatially to yield a functional cbb3-Cox enzyme. In this review we summarize our current knowledge on the structure, regulation and assembly of cbb3-Cox, and provide a highly tentative model for cbb3-Cox assembly and formation of its heme b3-CuB binuclear center.

Deciphering protein–protein interactions during the biogenesis of cytochrome c oxidase from Paracoccus denitrificans

“…The MS approach also identified further respiratory chain components that are known to assemble into supercomplexes, such as subunits of complexes I and III [28]. This also extends to subunits of the cbb 3 oxidase, an alternative terminal oxidase, in agreement with previously published data [42] where a common pathway for the biogenesis of COX and cbb 3 oxidase was suggested. Digitonin maintains the integrity of supercomplexes [28], while a harsher detergent such as DDM is expected to dissociate any respiratory supercomplex into its constituent respiratory complexes.…”

Expression of multiplecbb3cytochromecoxidase isoforms by combinations of multiple isosubunits inPseudomonas aeruginosa

“…These results indicate that P. aeruginosa gains resistance to respiratory inhibitors using multiple cbb 3 isoforms with different features, which are produced through exchanges of multiple core catalytic isosubunits. T he cbb 3 -type cytochrome c oxidase (cbb 3 ) is a bacteria-specific terminal oxidase of the heme-copper oxidoreductase superfamily that catalyzes the four-electron reduction of molecular oxygen to water at the end of the aerobic respiratory chain (1). cbb 3 has an extremely high affinity for oxygen and typically functions under low-oxygen conditions in many bacteria, including several pathogens of Helicobacter, Campylobacter, and Neisseria species (2)(3)(4).…”

Characterization of an ntrX Mutant of Neisseria gonorrhoeae Reveals a Response Regulator That Controls Expression of Respiratory Enzymes in Oxidase-Positive Proteobacteria

“…Enteric bacteria that only possess oxidases that directly oxidize ubiquinol, such as Escherichia coli, yield a negative oxidase test. An important characteristic of cytochrome cbb 3 is its remarkable affinity for oxygen, often being in the nM range (5,(8)(9)(10), with activity levels being highest under microaerobic or oxygen-limited conditions (8,11,12). Two-component systems (TCSs) composed of a sensor histidine kinase (SHK) and response regulator (RR) have emerged as key signal transducers and global regulators of gene expression in prokaryotes.…”