Expasy logo

ENZYME

ENZYME entry: EC 1.17.99.9

PURL: https://purl.expasy.org/enzyme/EC/1.17.99.9
Accepted Name
heme a synthase
Reaction catalysed
Fe(II)-heme o + 2 A + H2O = Fe(II)-heme a + 2 AH2
Comment(s)
  • Contains a heme b cofactor.
  • The enzyme catalyzes the conversion of heme o to heme a by two successive hydroxylations of the methyl group at C-8, using water as the oxygen source.
  • The first hydroxylation forms heme i, the second hydroxylation results in an unstable dihydroxymethyl group, which spontaneously dehydrates, resulting in the formyl group of heme a.
  • The electrons produced by the reaction are transferred to a heme b cofactor.
  • However, the electron acceptor that is used to restore the heme b cofactor to its oxidized state is still not known (both a thioredoxin-like protein and menaquinol have been proposed).
Cross-references
Rhea expert-curated reactions1.17.99.9
ExplorEnz1.17.99.9
IUBMB Enzyme Nomenclature1.17.99.9
UniProtKB/Swiss-Prot
Q9FKT8, COX15_ARATHQ08DG6, COX15_BOVINQ7KZN9, COX15_HUMAN
Q8BJ03, COX15_MOUSEP40086, COX15_YEASTA5FXV3, CTAA1_ACICJ
A5FXV4, CTAA2_ACICJQ7CZN9, CTAA_AGRFCQ04443, CTAA_ALKPO
B9JVB6, CTAA_ALLAMB9KHM9, CTAA_ANAMFQ5PBP7, CTAA_ANAMM
Q2GLK1, CTAA_ANAPZA8I7Y5, CTAA_AZOC5C3P6V3, CTAA_BACAA
C3LI12, CTAA_BACACA0RHW4, CTAA_BACAHQ81MT7, CTAA_BACAN
B7JK34, CTAA_BACC0Q732C1, CTAA_BACC1B7IVI3, CTAA_BACC2
C1EPW0, CTAA_BACC3B7H6T3, CTAA_BACC4B7HMD0, CTAA_BACC7
A7GRX4, CTAA_BACCNB9IW25, CTAA_BACCQQ819N0, CTAA_BACCR
Q635Y0, CTAA_BACCZQ6HEL8, CTAA_BACHKQ65K14, CTAA_BACLD
A9VUA7, CTAA_BACMKA8FCU5, CTAA_BACP2P12946, CTAA_BACSU
A7Z4B0, CTAA_BACVZA1USH8, CTAA_BARBKQ6G3L5, CTAA_BARHE
Q6G011, CTAA_BARQUA9IVC8, CTAA_BART1B2IH44, CTAA_BEII9
Q89KD9, CTAA_BRADUA5EKD5, CTAA_BRASBA4YVQ0, CTAA_BRASO
B2S532, CTAA_BRUA1Q2YNB0, CTAA_BRUA2A6X1W1, CTAA_BRUA4
Q57DW5, CTAA_BRUABA9MAG4, CTAA_BRUC2C0RIC2, CTAA_BRUMB
Q8YGI7, CTAA_BRUMEA5VPX0, CTAA_BRUO2B0CLB4, CTAA_BRUSI
Q8G1D1, CTAA_BRUSUB0T0S6, CTAA_CAUSKQ9A8H9, CTAA_CAUVC
B8H551, CTAA_CAUVNA3PQK0, CTAA_CERS1Q3IXW9, CTAA_CERS4
A4WZ55, CTAA_CERS5B9KW13, CTAA_CERSKQ11J69, CTAA_CHESB
A8LK55, CTAA_DINSHQ3YRB4, CTAA_EHRCJQ2GHG8, CTAA_EHRCR
Q5FG54, CTAA_EHRRGQ5HAH7, CTAA_EHRRWQ2GCS4, CTAA_EHRS3
Q2N6M9, CTAA_ERYLHB1YIW6, CTAA_EXIS2C4L5D6, CTAA_EXISA
A5FA69, CTAA_FLAJ1A6H039, CTAA_FLAPJQ5L115, CTAA_GEOKA
P94346, CTAA_GEOTDA4ILW9, CTAA_GEOTNA9HEV3, CTAA_GLUDA
Q0BQ20, CTAA_GRABCQ9K9M8, CTAA_HALH5Q0BZT0, CTAA_HYPNA
Q28PL3, CTAA_JANSCQ929V9, CTAA_LISINC1KX11, CTAA_LISMC
Q71XV6, CTAA_LISMFB8DH71, CTAA_LISMHQ8Y5K2, CTAA_LISMO
A0AKG4, CTAA_LISW6B1HPV0, CTAA_LYSSCB9EB26, CTAA_MACCJ
Q0APH6, CTAA_MARMMB7KV80, CTAA_METC4A9W350, CTAA_METEP
B8ISP2, CTAA_METNOB1ZGD8, CTAA_METPBB1M282, CTAA_METRJ
B0UR12, CTAA_METS4Q0AIG6, CTAA_NITECQ82X64, CTAA_NITEU
Q1QKJ7, CTAA_NITHXQ2Y9R4, CTAA_NITMUQ3SSR2, CTAA_NITWN
Q2G350, CTAA_NOVADQ8ER78, CTAA_OCEIHA5CF77, CTAA_ORITB
B3CRU7, CTAA_ORITIA1B8C2, CTAA_PARDPA7HXA1, CTAA_PARL1
Q2W552, CTAA_PARM1Q4FLV1, CTAA_PELUBB3PVH0, CTAA_RHIE6
Q2K9W9, CTAA_RHIECQ1MIP9, CTAA_RHIJ3Q982X5, CTAA_RHILO
B5ZXY9, CTAA_RHILWQ92QR8, CTAA_RHIMEB9JD11, CTAA_RHIR8
A5VF68, CTAA_RHIWRB6IUZ7, CTAA_RHOCSQ2IWP3, CTAA_RHOP2
Q07MP8, CTAA_RHOP5Q6N660, CTAA_RHOPAQ214F0, CTAA_RHOPB
Q136Q9, CTAA_RHOPSB3QKF4, CTAA_RHOPTC3PMV5, CTAA_RICAE
A8GMQ9, CTAA_RICAHA8GXM1, CTAA_RICB8Q1RJX8, CTAA_RICBR
A8EY08, CTAA_RICCKQ92IS7, CTAA_RICCNQ4UKQ2, CTAA_RICFE
A8F119, CTAA_RICM5Q9ZDR8, CTAA_RICPRB0BWT1, CTAA_RICRO
A8GRD0, CTAA_RICRSQ165T0, CTAA_ROSDOQ5LRS1, CTAA_RUEPO
Q1GGZ8, CTAA_RUESTQ8E8P8, CTAA_SHEONQ5WFD1, CTAA_SHOC1
C3MA28, CTAA_SINFNA6U7T3, CTAA_SINMWQ1GWK6, CTAA_SPHAL
A7X127, CTAA_STAA1A6U0T3, CTAA_STAA2Q2FHW5, CTAA_STAA3
Q2G2C0, CTAA_STAA8A5IS02, CTAA_STAA9Q2YX60, CTAA_STAAB
Q5HGW9, CTAA_STAACA6QFX0, CTAA_STAAEQ7A2S8, CTAA_STAAM
Q7A665, CTAA_STAANQ6GHX0, CTAA_STAARQ6GA99, CTAA_STAAS
A8Z1Q0, CTAA_STAATQ7A160, CTAA_STAAWB9DPV8, CTAA_STACT
Q5HQ52, CTAA_STAEQQ8CPM2, CTAA_STAESQ4L5C9, CTAA_STAHJ
Q49WP0, CTAA_STAS1Q67L43, CTAA_SYMTHQ73HV8, CTAA_WOLPM
B3CLF8, CTAA_WOLPPQ5GSI0, CTAA_WOLTRC0R5T8, CTAA_WOLWR
A7ING5, CTAA_XANP2Q10361, ETP1_SCHPO
BRENDA1.17.99.9
MetaCyc1.17.99.9
KEGG Ligand Database for Enzyme Nomenclature1.17.99.9
EC2PDB1.17.99.9
MEDLINEFind literature relating to 1.17.99.9

View entry in original ENZYME format
View entry in raw text format (no links)
All UniProtKB/Swiss-Prot entries referenced in this entry, with possibility to download in different formats, align etc.
All ENZYME / UniProtKB/Swiss-Prot entries corresponding to 1.17.99.-
All ENZYME / UniProtKB/Swiss-Prot entries corresponding to 1.17.-.-
All ENZYME / UniProtKB/Swiss-Prot entries corresponding to 1.-.-.-