EC                 Enzyme                                 

cyanocobalamin reductase;
MMACHC (gene name);
cyanocobalamin reductase (NADPH, cyanide-eliminating);
cyanocobalamin reductase (NADPH, CN-eliminating);
NADPH:cyanocob(III)alamin oxidoreductase (cyanide-eliminating);
cob(I)alamin, cyanide:NADP+ oxidoreductase;
cyanocobalamin reductase (cyanide-eliminating)
Oxidizing metal ions;
With NAD+ or NADP+ as acceptor
cob(II)alamin, hydrogen cyanide:NADP+ oxidoreductase
2 cob(II)alamin-[cyanocobalamin reductase] + 2 hydrogen cyanide + NADP+ = 2 cyanocob(III)alamin + 2 [cyanocobalamin reductase] + NADPH + H+ [RN:R02999]
cob(II)alamin-[cyanocobalamin reductase];
hydrogen cyanide [CPD:C01326];
NADP+ [CPD:C00006]
cyanocob(III)alamin [CPD:C02823];
[cyanocobalamin reductase];
NADPH [CPD:C00005];
H+ [CPD:C00080]
The mammalian enzyme, which is cytosolic, can bind internalized cyanocobalamin and process it to cob(II)alamin by removing the upper axial ligand. The product remains bound to the protein, which, together with its interacting partner MMADHC, transfers it directly to downstream enzymes involved in adenosylcobalamin and methylcobalamin biosynthesis. In addition to its decyanase function, the mammalian enzyme also catalyses an entirely different chemical reaction with alkylcobalamins, using the thiolate of glutathione for nucleophilic displacement, generating cob(I)alamin and the corresponding glutathione thioether (cf. EC, alkylcobalamin dealkylase).
EC created 1989 as EC, transferred 2002 to EC, modified 2018, modified 2021
ec00860  Porphyrin metabolism
ec01100  Metabolic pathways
K14618  cyanocobalamin reductase (cyanide-eliminating) / alkylcobalamin dealkylase
HSA: 25974(MMACHC)
PTR: 469180(MMACHC)
PPS: 100968335(MMACHC)
GGO: 101152807(MMACHC)
PON: 100455100(MMACHC)
NLE: 100580574(MMACHC)
MCC: 706247(MMACHC)
MCF: 102121304(MMACHC)
CSAB: 103224912(MMACHC)
CATY: 105594589(MMACHC)
PANU: 100999738(MMACHC) 101002954
RRO: 104662137(MMACHC)
RBB: 108535651(MMACHC)
TFN: 117092676(MMACHC)
PTEH: 111548761(MMACHC)
CJC: 100399324(MMACHC)
SBQ: 101027482(MMACHC)
MMUR: 105877469(MMACHC)
MMU: 67096(Mmachc)
MCAL: 110293555(Mmachc)
MPAH: 110323588(Mmachc)
RNO: 313520(Mmachc)
MCOC: 116096478(Mmachc)
MUN: 110546536(Mmachc)
CGE: 100751045(Mmachc)
PLEU: 114707071(Mmachc)
NGI: 103737785(Mmachc)
HGL: 101709397(Mmachc)
CPOC: 100735601(Mmachc)
OCU: 100347413(MMACHC)
OPI: 101526373(MMACHC)
TUP: 102472726(MMACHC)
CFA: 482514(MMACHC)
VVP: 112914783(MMACHC)
VLG: 121481537(MMACHC)
AML: 100466484(MMACHC)
UMR: 103670776(MMACHC)
UAH: 113254743(MMACHC)
ORO: 101379031(MMACHC)
ELK: 111142962
MPUF: 101689342(MMACHC)
EJU: 114224136(MMACHC)
MLX: 118019481(MMACHC)
FCA: 101090955(MMACHC)
PYU: 121027034(MMACHC)
PBG: 122480425(MMACHC)
PTG: 102954225(MMACHC)
PPAD: 109266970(MMACHC)
AJU: 106970243(MMACHC)
HHV: 120247062(MMACHC)
BTA: 513433(MMACHC)
BOM: 102277584(MMACHC)
BIU: 109556357(MMACHC)
BBUB: 102401472(MMACHC)
CHX: 102183931(MMACHC)
OAS: 101120707(MMACHC)
ODA: 120856239(MMACHC)
CCAD: 122436862 122437053(MMACHC)
SSC: 100513159(MMACHC)
CFR: 102509232(MMACHC)
CBAI: 105065473(MMACHC)
CDK: 105090870(MMACHC)
BACU: 103014111(MMACHC)
LVE: 103075700(MMACHC)
OOR: 101274733(MMACHC)
DLE: 111175748(MMACHC)
PCAD: 102979216(MMACHC)
PSIU: 116741286(MMACHC)
ECB: 100065336(MMACHC)
EPZ: 103551877(MMACHC)
EAI: 106826139(MMACHC)
MYB: 102260677(MMACHC)
MYD: 102764382(MMACHC)
MMYO: 118677675(MMACHC)
MLF: 102431183(MMACHC)
MNA: 107526768(MMACHC)
PKL: 118724531(MMACHC)
HAI: 109375517(MMACHC)
DRO: 112314606(MMACHC)
SHON: 118982442(MMACHC)
AJM: 119052514(MMACHC)
PDIC: 114496741(MMACHC)
MMF: 118626637(MMACHC)
RFQ: 117026819(MMACHC)
PALE: 102888849(MMACHC)
PGIG: 120620111(MMACHC)
RAY: 107506891(MMACHC)
MJV: 108385733(MMACHC)
TOD: 119236402(MMACHC)
LAV: 100673499(MMACHC)
TMU: 101353030
MDO: 100024700(MMACHC)
GAS: 123245274(MMACHC)
SHR: 100914568(MMACHC)
PCW: 110209280(MMACHC)
OAA: 100077154(MMACHC)
GGA: 424597(MMACHC)
PCOC: 116234140(MMACHC)
MGP: 100547376(MMACHC)
CJO: 107317442(MMACHC)
NMEL: 110402950(MMACHC)
APLA: 101804029(MMACHC)
ACYG: 106033094(MMACHC)
TGU: 105759460(MMACHC)
LSR: 110469630(MMACHC)
SCAN: 103815175(MMACHC)
PMOA: 120503263(MMACHC)
OTC: 121345068(MMACHC)
PRUF: 121362233(MMACHC)
GFR: 102038500(MMACHC)
FAB: 101815080(MMACHC)
PHI: 102110636(MMACHC)
PMAJ: 107208008(MMACHC)
CCAE: 111933112(MMACHC)
CCW: 104695241(MMACHC)
ETL: 114062118(MMACHC)
FPG: 101914760(MMACHC)
FCH: 102058033(MMACHC)
CLV: 102088492(MMACHC)
EGZ: 104126262(MMACHC)
NNI: 104015417(MMACHC)
ACUN: 113482722(MMACHC)
PADL: 103919135(MMACHC)
AAM: 106485930(MMACHC)
AROW: 112975991(MMACHC)
NPD: 112942572(MMACHC)
DNE: 112985541(MMACHC)
ASN: 102383499(MMACHC)
AMJ: 102560477(MMACHC)
CPOO: 109307416(MMACHC)
GGN: 109286722(MMACHC)
PSS: 102459461(MMACHC)
CMY: 102936214(MMACHC)
CPIC: 101952441(MMACHC)
TST: 117881958(MMACHC)
CABI: 116838969(MMACHC)
MRV: 120370022(MMACHC)
ACS: 100552851(mmachc)
PVT: 110073759(MMACHC)
SUND: 121928329(MMACHC)
PBI: 103063544(MMACHC)
PMUR: 107283422(MMACHC)
TSR: 106548837(MMACHC)
PGUT: 117664138(MMACHC)
VKO: 123029289(MMACHC)
PMUA: 114599088(MMACHC)
ZVI: 118088724(MMACHC)
GJA: 107107920(MMACHC)
XLA: 100127331(mmachc.L)
XTR: 549685(mmachc)
NPR: 108800338(MMACHC)
DRE: 555267(mmachc)
SRX: 107757670(mmachc)
SANH: 107653140(mmachc)
SGH: 107565041(mmachc)
CCAR: 109051604(mmachc)
CAUA: 113037680(mmachc)
IPU: 100528283(mmachc)
PHYP: 113546876(mmachc)
AMEX: 103032715(mmachc)
EEE: 113591323(mmachc)
TRU: 101073402(mmachc)
LCO: 104926001(mmachc)
NCC: 104967760(mmachc)
CGOB: 115006728(mmachc)
ELY: 117253630(mmachc)
PLEP: 121941263(mmachc)
SLUC: 116063239(mmachc)
ECRA: 117950442(mmachc)
PFLV: 114562020(mmachc)
GAT: 120823682(mmachc)
PPUG: 119216598(mmachc)
MSAM: 119900990(mmachc)
CUD: 121511797(mmachc)
MZE: 101475866(mmachc)
ONL: 100705297(mmachc)
OAU: 116331220(mmachc)
OLA: 101155593(mmachc)
OML: 112150160(mmachc)
XMA: 102223263(mmachc)
XCO: 114150362(mmachc)
XHE: 116725181(mmachc)
PRET: 103463749(mmachc)
GAF: 122838399(mmachc)
CVG: 107096364(mmachc)
CTUL: 119799275(mmachc)
NFU: 107396398(mmachc)
KMR: 108230696(mmachc)
ALIM: 106533393(mmachc)
AOCE: 111564984(mmachc)
CSEM: 103376733(mmachc)
POV: 109625330(mmachc)
SSEN: 122780298(mmachc)
HHIP: 117760846(mmachc)
LCF: 108879008(mmachc)
SDU: 111231994(mmachc)
SLAL: 111653738(mmachc)
XGL: 120791223(mmachc)
HCQ: 109532243(mmachc)
BPEC: 110154834(mmachc)
MALB: 109974876(mmachc)
SASA: 100196847(mmachc)
OTW: 112251067(mmachc)
OMY: 110524489(mmachc)
SALP: 111975270(mmachc)
SNH: 120054506(mmachc)
ELS: 105011679(mmachc)
SFM: 108923522(mmachc)
PKI: 111834817(mmachc)
AANG: 118225447(mmachc)
LOC: 102684271(mmachc)
PSPA: 121326789(mmachc)
ARUT: 117416980(mmachc)
LCM: 102353117(MMACHC)
CMK: 103182780(mmachc)
BFO: 118431891
BBEL: 109476117
CIN: 100181296
SCLV: 120342038
SPU: 575015
APLC: 110989375
SKO: 100368262
FCD: 110861518
DMK: 116919432
HAME: 121863227
HAZT: 108667502
EAF: 111706502
DSV: 119433119
RSAN: 119404023
RMP: 119180682
DPTE: 113791070
SDM: 118183440
CEL: CELE_ZK546.17(cblc-1)
CBR: CBG_28142
TSP: Tsp_00699
PCAN: 112574267
BGT: 106064335
CRG: 105331412
MYI: 110443657
PMAX: 117325773
OSN: 115232349
LAK: 106178486
NVE: 5510973
EPA: 110237339
ATEN: 116307974
ADF: 107347741
AMIL: 114956024
PDAM: 113667854
SPIS: 111334144
DGT: 114526387
HMG: 100212172
AQU: 100641773
AHF: 112754217
 » show all
1  [PMID:3134526]
Watanabe F, Oki Y, Nakano Y, Kitaoka S.
Occurrence and characterization of cyanocobalamin reductase (NADPH; CN-eliminating) involved in decyanation of cyanocobalamin in Euglena gracilis.
J Nutr Sci Vitaminol (Tokyo) 34:1-10 (1988)
2  [PMID:18779575]
Kim J, Gherasim C, Banerjee R
Decyanation of vitamin B12 by a trafficking chaperone.
Proc Natl Acad Sci U S A 105:14551-4 (2008)
3  [PMID:21697092]
Koutmos M, Gherasim C, Smith JL, Banerjee R
Structural basis of multifunctionality in a vitamin B12-processing enzyme.
J Biol Chem 286:29780-7 (2011)
4  [PMID:23270877]
Mah W, Deme JC, Watkins D, Fung S, Janer A, Shoubridge EA, Rosenblatt DS, Coulton JW
Subcellular location of MMACHC and MMADHC, two human proteins central to intracellular vitamin B(12) metabolism.
Mol Genet Metab 108:112-8 (2013)
Other DBs
ExplorEnz - The Enzyme Database:
IUBMB Enzyme Nomenclature:
ExPASy - ENZYME nomenclature database:
BRENDA, the Enzyme Database:
CAS: 131145-00-1

DBGET integrated database retrieval system