Cytochrome b558 alpha-subunit (IPR007732)

Short name: Cyt_b558_asu

Overlapping homologous superfamilies


Family relationships



Flavocytochrome b558 is the catalytic core of the respiratory-burst oxidase, an enzyme complex that catalyzes the NADPH-dependent reduction of O2 into the superoxide anion O2 in phagocytic cells. Flavocytochrome b558 is anchored in the plasma membrane. It is a heterodimer that consists of a large glycoprotein gp91phox (phox forphagocyte oxidase) (beta subunit) and a small protein p22phox (alpha subunit). The other components of the respiratory-burst oxidase are water-soluble proteins of cytosolic origin, namely p67phox, p47phox, p40phox and Rac. Upon cell stimulation, they assemble with the membrane-bound flavocytochrome b558 which becomes activated and generates O2- [PMID: 8798532].

GO terms

Biological Process

No terms assigned in this category.

Molecular Function

GO:0020037 heme binding

Cellular Component

No terms assigned in this category.

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.