Holocytochrome-c synthase

The enzyme holocytochrome-c synthase (EC 4.4.1.17) catalyzes the chemical reaction

holocytochrome c ${\displaystyle \rightleftharpoons }$ apocytochrome c + heme

holocytochrome-c synthase
Holocytochrome-c synthase monomer, Thermus thermophilus
Identifiers
EC no.	4.4.1.17
CAS no.	75139-03-6
Databases
IntEnz	IntEnz view
BRENDA	BRENDA entry
ExPASy	NiceZyme view
KEGG	KEGG entry
MetaCyc	metabolic pathway
PRIAM	profile
PDB structures	RCSB PDB PDBe PDBsum
Gene Ontology	AmiGO / QuickGO
Search PMC articles PubMed articles NCBI proteins

Cytochrome c/c1 heme lyase
Identifiers
Symbol	Cyto_heme_lyase
Pfam	PF01265
InterPro	IPR000511
PROSITE	PDOC00647
Available protein structures: Pfam   structures / ECOD   PDB RCSB PDB; PDBe; PDBj PDBsum structure summary

This enzyme belongs to the family of lyases, specifically the class of carbon-sulfur lyases. The systematic name of this enzyme class is holocytochrome-c apocytochrome-c-lyase (heme-forming). Other names in common use include cytochrome c heme-lyase, holocytochrome c synthetase, and holocytochrome-c apocytochrome-c-lyase. This enzyme participates in porphyrin and chlorophyll metabolism.

Cytochrome c heme-lyase (CCHL) and cytochrome Cc1 heme-lyase (CC1HL) are mitochondrial enzymes that catalyze the covalent attachment of a heme group on two cysteine residues of cytochrome c and c1. These two enzymes are functionally and evolutionary related. There are two conserved regions, the first is located in the central section and the second in the C-terminal section. Both patterns contain conserved histidine, tryptophan and acidic residues which could be important for the interaction of the enzymes with the apoproteins and/or the heme group.^[1]

The human enzyme, HCCS, processes both cytochromes c and c1.^[2]