Cofactor assembly of complex C subunit B, CCB2/CCB4
Cofactor maturation pathways such as the CCB system (system IV) for cytochrome c-heme attachment are conserved in all organisms performing oxygenic photosynthesis. The CCB system consists of four proteins: CCB1-4. CCB2 and CCB4 are paralogues derived from a unique cyanobacterial ancestor. Orthologues are conserved in higher plants.