Cloned (Comment) | Organism |
---|---|
recombinant coexpression of the GST-tagged enzyme with cytochrome c mutants, containing individual cysteine, histidine, double cysteine, and triple cysteine/histidine substitutions of conserved motif CXXCH, in Escherichia coli strain RK103 membranes, single and double mutants form a complex with the enzyme but not the triple mutant | Homo sapiens |
Protein Variants | Comment | Organism |
---|---|---|
C15S | the HCCS:cyt c C15S and C18A mutants support the formation of single thioether cross-links between the heme and cyt c at the vinyl position alternate to the mutation | Homo sapiens |
C18A | the HCCS:cyt c C15S and C18A mutants support the formation of single thioether cross-links between the heme and cyt c at the vinyl position alternate to the mutation | Homo sapiens |
Localization | Comment | Organism | GeneOntology No. | Textmining |
---|---|---|---|---|
mitochondrion | - |
Homo sapiens | 5739 | - |
Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|
Apocytochrome c + heme | Homo sapiens | - |
Holocytochrome c | - |
? |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Homo sapiens | P53701 | - |
- |
Purification (Comment) | Organism |
---|---|
recombinant GST-tagged enzyme and cytochrome c mutants from Escherichia coli strain RK103 membranes by ultracentrifugation, glutahione affinity chromatographyand ultrafiltration | Homo sapiens |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
Apocytochrome c + heme | - |
Homo sapiens | Holocytochrome c | - |
? | |
Apocytochrome c + heme | the enzyme attaches heme to wild-type cytochrome, and to mutant cytochromes containing individual cysteine, histidine, and double cysteine of conserved motif CXXCH, but not the mutant with triple cysteine/histidine substitutions, overview. His19 in cytochrome c is important for 1. to provide the second axial ligand to the heme iron in preparation for covalent attachment, 2. to spatially position the two cysteinyl sulfurs adjacent to the two heme vinyl groups for thioether formation, and 3. to aid in release of the holocytochrome c from the enzyme's active site. Substitutions of His19 in cytochrome c to seven other residues (G,A,M,R,K,C,Y) show that only mutant H19M is able to carry out these three roles, albeit at lower efficiencies than the wild-type His19. The histidine in the CXXCH motif acts as an axial ligand to the heme iron | Homo sapiens | Holocytochrome c | - |
? |
Synonyms | Comment | Organism |
---|---|---|
HCCS | - |
Homo sapiens |
holocytochrome c synthase | - |
Homo sapiens |
General Information | Comment | Organism |
---|---|---|
physiological function | for mitochondrial cytochrome c assembly, the enzyme binds heme and apocytochrome c substrate to catalyze a covalent attachment of heme by thioether bonds between heme vinyl groups and a conserved CXXCH motif of cytochrome c/c1, and subsequently releases holocytochrome c for proper folding to its native structure, mechanism of assembly, overview | Homo sapiens |