Methylmalonic aciduria type A protein, mitochondrial (EC 3.6.-.-)
1_MPMLL 6_ PHPHQ 11_ HFLKG 16_ LLRAP 21_ FRCYH 26_ FIFHS 31_ STHLG 36_ SGIPC 41_ AQPFN 46_ SLGLH 51_ CTKWM 56_ LLSDG 61_ LKRKL 66_ CVQTT 71_ LKDHT 76_ EGLSD 81_ KEQRF 86_ VDKLY 91_ TGLIQ 96_ GQRAC 101_ LAEAI 106_ TLVES 111_ THSRK 116_ KELAQ 121_ VLLQK 126_ VLLYH 131_ REQEQ 136_ SNKGK 141_ PLAFR 146_ VGLSG 151_ PPGAG 156_ KSTFI 161_ EYFGK 166_ MLTER 171_ GHKLS 176_ VLAVD 181_ PSSCT 186_ SGGSL 191_ LGDKT 196_ RMTEL 201_ SRDMN 206_ AYIRP 211_ SPTRG 216_ TLGGV 221_ TRTTN 226_ EAILL 231_ CEGAG 236_ YDIIL 241_ IETVG 246_ VGQSE 251_ FAVAD 256_ MVDMF 261_ VLLLP 266_ PAGGD 271_ ELQGI 276_ KRGII 281_ EMADL 286_ VAVTK 291_ SDGDL 296_ IVPAR 301_ RIQAE 306_ YVSAL 311_ KLLRK 316_ RSQVW 321_ KPKVI 326_ RISAR 331_ SGEGI 336_ SEMWD 341_ KMKDF 346_ QDLML 351_ ASGEL 356_ TAKRR 361_ KQQKV 366_ WMWNL 371_ IQESV 376_ LEHFR 381_ THPTV 386_ REQIP 391_ LLEQK 396_ VLIGA 401_ LSPGL 406_ AADFL 411_LKAFK
1: GTPase, binds and hydrolyzes GTP (PubMed:20876572, PubMed:21138732, PubMed:28497574, PubMed:28943303). Involved in intracellular vitamin B12 metabolism, mediates the transport of cobalamin (Cbl) into mitochondria for the final steps of adenosylcobalamin (AdoCbl) synthesis (PubMed:20876572, PubMed:28497574). Functions as a G-protein chaperone that assists AdoCbl cofactor delivery from MMAB to the methylmalonyl-CoA mutase (MMUT) (PubMed:20876572, PubMed:28497574). Plays a dual role as both a protectase and a reactivase for MMUT (PubMed:21138732, PubMed:28943303). Protects MMUT from progressive inactivation by oxidation by decreasing the rate of the formation of the oxidized inactive cofactor hydroxocobalamin (OH2Cbl) (PubMed:21138732, PubMed:28943303). 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 (PubMed:21138732, PubMed:28943303)