MMACHC

Methylmalonic aciduria and homocystinuria type C protein (MMACHC) is a protein that in humans is encoded by the MMACHC gene.^[5]

MMACHC
Available structures PDB Ortholog search: PDBe RCSB List of PDB id codes 3SBY, 3SBZ, 3SC0, 3SOM
Identifiers
Aliases	MMACHC, cblC, methylmalonic aciduria (cobalamin deficiency) cblC type, with homocystinuria, metabolism of cobalamin associated C
External IDs	OMIM: 609831; MGI: 1914346; HomoloGene: 12082; GeneCards: MMACHC; OMA:MMACHC - orthologs
Gene location (Human) Chr. Chromosome 1 (human)[1] Band 1p34.1 Start 45,500,300 bp[1] End 45,513,382 bp[1]
Gene location (Mouse) Chr. Chromosome 4 (mouse)[2] Band 4|4 D1 Start 116,559,476 bp[2] End 116,565,603 bp[2]
RNA expression pattern Bgee Human Mouse (ortholog) Top expressed in right lobe of liver muscle of thigh stromal cell of endometrium ventricular zone mucosa of transverse colon testicle right auricle of heart left ventricle prefrontal cortex right adrenal gland Top expressed in myocardium of ventricle sternocleidomastoid muscle soleus muscle digastric muscle temporal muscle tibialis anterior muscle triceps brachii muscle vastus lateralis muscle extraocular muscle gastrocnemius muscle More reference expression data BioGPS n/a
Gene ontology Molecular function cobalamin binding protein binding FAD binding demethylase activity protein homodimerization activity glutathione binding cyanocobalamin reductase (cyanide-eliminating) activity oxidoreductase activity Cellular component cytosol cytoplasm Biological process demethylation glutathione metabolic process cobalamin biosynthetic process cobalamin metabolic process Sources:Amigo / QuickGO
Orthologs Species Human Mouse Entrez 25974 67096 Ensembl ENSG00000132763 ENSMUSG00000028690 UniProt Q9Y4U1 Q9CZD0 RefSeq (mRNA) NM_015506 NM_001330540 NM_025962 RefSeq (protein) NP_001317469 NP_056321 NP_080238 Location (UCSC) Chr 1: 45.5 – 45.51 Mb Chr 4: 116.56 – 116.57 Mb PubMed search [3] [4]
Wikidata
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Function

The C-terminal region of the product of the MMACHC gene is similar to TonB, a bacterial protein involved in energy transduction for cobalamin uptake.^[5] The MMACHC gene product catalyzes the decyanation of cyanocobalamin as well as the dealkylation of alkylcobalamins including methylcobalamin and adenosylcobalamin.^[6] This function has also been attributed to cobalamin reductases.^[7] The MMACHC gene product and cobalamin reductases enable the interconversion of cyano- and alkylcobalamins.^[8][9]

Clinical significance

Mutations are associated with combined homocystinuria and methylmalonic acidemia.^{[5][10][11][12][13]}