Loading the page.
Proteins/UNIPROT:Q8IVH4
GTPase, binds and hydrolyzes GTP. Involved in intracellular vitamin B12 metabolism, mediates the transport of cobalamin (Cbl) into mitochondria for the final steps of adenosylcobalamin (AdoCbl) synthesis. Functions as a G protein chaperone that assists AdoCbl cofactor delivery from MMAB to the methylmalonyl-CoA mutase (MMUT). Plays a dual role as both a protectase and a reactivase for MMUT. Protects MMUT from progressive inactivation by oxidation by decreasing the rate of the formation of the oxidized inactive cofactor hydroxocobalamin (OH2Cbl). Additionally acts a reactivase by promoting the replacement of OH2Cbl by the active cofactor AdoCbl, restoring the activity of MMUT in the presence and hydrolysis of GTP..
Function from UniProtKB (Q8IVH4), read 2026-09-23. CC BY 4.0.
Curated compounds routed: 0
1 row
22 statements
22 statements · 4 reference databases · Subject: MMAA · Sources: Hetionet, Human-GEM, Reactome, WikiPathways
4 reactions
Transported by MMAA
Reaction pageLeft to rightBalancedcytosol, mitochondrial matrix
Human-GEM MAR08614CC BY 4.0Reference data
cob(II)alamin+NADH(2-)MAM01598m+proton+NAD(+)
Reaction pageReversibleUnbalancedEC 2.5.1.17mitochondrial matrix
1 name
Resolves to: MMAA
ATP+MAM01598m+protonMAM01600m+triphosphate
Reaction pageReversibleBalancedEC 2.5.1.17mitochondrial matrix
Human-GEM MAR08616CC BY 4.0Reference data
GTP+waterGDP+hydrogenphosphate+hydron
Catalysed by IRGM or RAB19 or TUBAL3 or GTPBP1 or RAB27B or RHOD or DNM1L or MRAS or RAB29 or OPA1 or EIF5B or ENTPD3 and 183 more alternatives
Reaction pageLeft to rightBalanced
Rhea RHEA:19669CC BY 4.0Reference data