Disease relevance of exaB

• The regulation of the divergent promoters of the exaAB genes in Pseudomonas aeruginosa ATCC 17933, in which exaA encodes a quinoprotein ethanol dehydrogenase and exaB codes for a cytochrome c(550), was studied [1].
• The exposed edge of the heme in the C-terminal domain is surrounded by several different patterns of charged residues in the Paracoccus and Pseudomonas enzymes, and this is consistent with the interaction of the former with the highly positively charged front face of the donor cytochrome c-550 [2].

High impact information on exaB

• Cytochrome c550 mediates electron transfer between quinoprotein ethanol dehydrogenase and ferricyanide [3].
• In a system composed of membrane particles with NN'NN'-tetramethyl-p-phenylenediamine oxidase activity and quinoprotein ethanol dehydrogenase, oxygen consumption is only observed in the presence of cytochrome c550 [3].
• The visible-absorption spectra of the enzyme closely resemble those of cytochrome c peroxidase from Pseudomonas aeruginosa but the donor specificity is different, with the Pa. denitrificans enzyme preferring the basic mitochondrial cytochromes c to the acidic cytochromes c-551 and reacting well with the Pa. denitrificans cytochrome c-550 [4].

Biological context of exaB

• This difference between cytochrome c-550 and mitochondrial cytochrome c may reflect subtle differences in their electron transport roles [5].

Associations of exaB with chemical compounds

• A truncated ORF encoding the quinoprotein ethanol dehydrogenase (exaA) was found upstream of the cytochrome c550 gene (exaB) and in reverse orientation [6].

References