ID A9V1Z5_MONBE Unreviewed; 1268 AA.
AC A9V1Z5;
DT 05-FEB-2008, integrated into UniProtKB/TrEMBL.
DT 05-FEB-2008, sequence version 1.
DT 27-MAR-2024, entry version 96.
DE RecName: Full=Methionine synthase {ECO:0000256|ARBA:ARBA00012032, ECO:0000256|PIRNR:PIRNR000381};
DE EC=2.1.1.13 {ECO:0000256|ARBA:ARBA00012032, ECO:0000256|PIRNR:PIRNR000381};
DE AltName: Full=5-methyltetrahydrofolate--homocysteine methyltransferase {ECO:0000256|PIRNR:PIRNR000381};
GN ORFNames=MONBRDRAFT_37476 {ECO:0000313|EMBL:EDQ88652.1};
OS Monosiga brevicollis (Choanoflagellate).
OC Eukaryota; Choanoflagellata; Craspedida; Salpingoecidae; Monosiga.
OX NCBI_TaxID=81824 {ECO:0000313|EMBL:EDQ88652.1, ECO:0000313|Proteomes:UP000001357};
RN [1] {ECO:0000313|EMBL:EDQ88652.1, ECO:0000313|Proteomes:UP000001357}
RP NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC STRAIN=MX1 / ATCC 50154 {ECO:0000313|Proteomes:UP000001357};
RX PubMed=18273011; DOI=10.1038/nature06617;
RG JGI Sequencing;
RA King N., Westbrook M.J., Young S.L., Kuo A., Abedin M., Chapman J.,
RA Fairclough S., Hellsten U., Isogai Y., Letunic I., Marr M., Pincus D.,
RA Putnam N., Rokas A., Wright K.J., Zuzow R., Dirks W., Good M.,
RA Goodstein D., Lemons D., Li W., Lyons J.B., Morris A., Nichols S.,
RA Richter D.J., Salamov A., Bork P., Lim W.A., Manning G., Miller W.T.,
RA McGinnis W., Shapiro H., Tjian R., Grigoriev I.V., Rokhsar D.;
RT "The genome of the choanoflagellate Monosiga brevicollis and the origin of
RT metazoans.";
RL Nature 451:783-788(2008).
CC -!- FUNCTION: Catalyzes the transfer of a methyl group from methyl-
CC cobalamin to homocysteine, yielding enzyme-bound cob(I)alamin and
CC methionine. Subsequently, remethylates the cofactor using
CC methyltetrahydrofolate. {ECO:0000256|PIRNR:PIRNR000381}.
CC -!- CATALYTIC ACTIVITY:
CC Reaction=(6S)-5-methyl-5,6,7,8-tetrahydrofolate + L-homocysteine =
CC (6S)-5,6,7,8-tetrahydrofolate + L-methionine; Xref=Rhea:RHEA:11172,
CC ChEBI:CHEBI:18608, ChEBI:CHEBI:57453, ChEBI:CHEBI:57844,
CC ChEBI:CHEBI:58199; EC=2.1.1.13;
CC Evidence={ECO:0000256|PIRNR:PIRNR000381};
CC -!- COFACTOR:
CC Name=Zn(2+); Xref=ChEBI:CHEBI:29105;
CC Evidence={ECO:0000256|ARBA:ARBA00001947,
CC ECO:0000256|PIRNR:PIRNR000381, ECO:0000256|PROSITE-ProRule:PRU00333};
CC -!- COFACTOR:
CC Name=methylcob(III)alamin; Xref=ChEBI:CHEBI:28115;
CC Evidence={ECO:0000256|ARBA:ARBA00001956,
CC ECO:0000256|PIRNR:PIRNR000381, ECO:0000256|PIRSR:PIRSR000381-1};
CC -!- PATHWAY: Amino-acid biosynthesis; L-methionine biosynthesis via de novo
CC pathway; L-methionine from L-homocysteine (MetH route): step 1/1.
CC {ECO:0000256|ARBA:ARBA00005178, ECO:0000256|PIRNR:PIRNR000381}.
CC -!- DOMAIN: Modular enzyme with four functionally distinct domains. The
CC isolated Hcy-binding domain catalyzes methyl transfer from free
CC methylcobalamin to homocysteine. The Hcy-binding domain in association
CC with the pterin-binding domain catalyzes the methylation of
CC cob(I)alamin by methyltetrahydrofolate and the methylation of
CC homocysteine. The B12-binding domain binds the cofactor. The AdoMet
CC activation domain binds S-adenosyl-L-methionine. Under aerobic
CC conditions cob(I)alamin can be converted to inactive cob(II)alamin.
CC Reductive methylation by S-adenosyl-L-methionine and flavodoxin
CC regenerates methylcobalamin. {ECO:0000256|PIRNR:PIRNR000381}.
CC -!- SIMILARITY: Belongs to the vitamin-B12 dependent methionine synthase
CC family. {ECO:0000256|ARBA:ARBA00010398}.
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DR EMBL; CH991554; EDQ88652.1; -; Genomic_DNA.
DR RefSeq; XP_001746756.1; XM_001746704.1.
DR AlphaFoldDB; A9V1Z5; -.
DR STRING; 81824.A9V1Z5; -.
DR EnsemblProtists; EDQ88652; EDQ88652; MONBRDRAFT_37476.
DR GeneID; 5891877; -.
DR KEGG; mbr:MONBRDRAFT_37476; -.
DR eggNOG; KOG1579; Eukaryota.
DR InParanoid; A9V1Z5; -.
DR OMA; ADCIAMS; -.
DR UniPathway; UPA00051; UER00081.
DR Proteomes; UP000001357; Unassembled WGS sequence.
DR GO; GO:0005829; C:cytosol; IBA:GO_Central.
DR GO; GO:0031419; F:cobalamin binding; IEA:UniProtKB-UniRule.
DR GO; GO:0008705; F:methionine synthase activity; IBA:GO_Central.
DR GO; GO:0008270; F:zinc ion binding; IEA:UniProtKB-UniRule.
DR GO; GO:0050667; P:homocysteine metabolic process; IBA:GO_Central.
DR GO; GO:0009086; P:methionine biosynthetic process; IBA:GO_Central.
DR GO; GO:0032259; P:methylation; IEA:UniProtKB-KW.
DR GO; GO:0046653; P:tetrahydrofolate metabolic process; IBA:GO_Central.
DR CDD; cd02069; methionine_synthase_B12_BD; 1.
DR CDD; cd00740; MeTr; 1.
DR Gene3D; 3.40.50.280; Cobalamin-binding domain; 1.
DR Gene3D; 1.10.288.10; Cobalamin-dependent Methionine Synthase, domain 2; 1.
DR Gene3D; 3.20.20.20; Dihydropteroate synthase-like; 1.
DR Gene3D; 3.20.20.330; Homocysteine-binding-like domain; 1.
DR Gene3D; 1.10.1240.10; Methionine synthase domain; 1.
DR Gene3D; 3.10.196.10; Vitamin B12-dependent methionine synthase, activation domain; 1.
DR InterPro; IPR003759; Cbl-bd_cap.
DR InterPro; IPR006158; Cobalamin-bd.
DR InterPro; IPR036724; Cobalamin-bd_sf.
DR InterPro; IPR011005; Dihydropteroate_synth-like_sf.
DR InterPro; IPR003726; HCY_dom.
DR InterPro; IPR036589; HCY_dom_sf.
DR InterPro; IPR033706; Met_synthase_B12-bd.
DR InterPro; IPR011822; MetH.
DR InterPro; IPR036594; Meth_synthase_dom.
DR InterPro; IPR000489; Pterin-binding_dom.
DR InterPro; IPR004223; VitB12-dep_Met_synth_activ_dom.
DR InterPro; IPR037010; VitB12-dep_Met_synth_activ_sf.
DR NCBIfam; TIGR02082; metH; 1.
DR PANTHER; PTHR45833; METHIONINE SYNTHASE; 1.
DR PANTHER; PTHR45833:SF1; METHIONINE SYNTHASE; 1.
DR Pfam; PF02310; B12-binding; 1.
DR Pfam; PF02607; B12-binding_2; 1.
DR Pfam; PF02965; Met_synt_B12; 1.
DR Pfam; PF00809; Pterin_bind; 1.
DR Pfam; PF02574; S-methyl_trans; 1.
DR PIRSF; PIRSF000381; MetH; 1.
DR SMART; SM01018; B12-binding_2; 1.
DR SUPFAM; SSF52242; Cobalamin (vitamin B12)-binding domain; 1.
DR SUPFAM; SSF51717; Dihydropteroate synthetase-like; 1.
DR SUPFAM; SSF82282; Homocysteine S-methyltransferase; 1.
DR SUPFAM; SSF56507; Methionine synthase activation domain-like; 1.
DR SUPFAM; SSF47644; Methionine synthase domain; 1.
DR PROSITE; PS50974; ADOMET_ACTIVATION; 1.
DR PROSITE; PS51332; B12_BINDING; 1.
DR PROSITE; PS51337; B12_BINDING_NTER; 1.
DR PROSITE; PS50970; HCY; 1.
DR PROSITE; PS50972; PTERIN_BINDING; 1.
PE 3: Inferred from homology;
KW Amino-acid biosynthesis {ECO:0000256|ARBA:ARBA00022605,
KW ECO:0000256|PIRNR:PIRNR000381};
KW Cobalamin {ECO:0000256|ARBA:ARBA00022628, ECO:0000256|PIRNR:PIRNR000381};
KW Cobalt {ECO:0000256|ARBA:ARBA00023285, ECO:0000256|PIRNR:PIRNR000381};
KW Coiled coil {ECO:0000256|SAM:Coils};
KW Metal-binding {ECO:0000256|ARBA:ARBA00022723,
KW ECO:0000256|PIRNR:PIRNR000381};
KW Methionine biosynthesis {ECO:0000256|ARBA:ARBA00023167,
KW ECO:0000256|PIRNR:PIRNR000381};
KW Methyltransferase {ECO:0000256|ARBA:ARBA00022603,
KW ECO:0000256|PIRNR:PIRNR000381};
KW Reference proteome {ECO:0000313|Proteomes:UP000001357};
KW Repeat {ECO:0000256|ARBA:ARBA00022737};
KW S-adenosyl-L-methionine {ECO:0000256|ARBA:ARBA00022691,
KW ECO:0000256|PIRNR:PIRNR000381};
KW Transferase {ECO:0000256|ARBA:ARBA00022679, ECO:0000256|PIRNR:PIRNR000381};
KW Zinc {ECO:0000256|ARBA:ARBA00022833, ECO:0000256|PIRNR:PIRNR000381}.
FT DOMAIN 19..338
FT /note="Hcy-binding"
FT /evidence="ECO:0000259|PROSITE:PS50970"
FT DOMAIN 371..632
FT /note="Pterin-binding"
FT /evidence="ECO:0000259|PROSITE:PS50972"
FT DOMAIN 662..759
FT /note="B12-binding N-terminal"
FT /evidence="ECO:0000259|PROSITE:PS51337"
FT DOMAIN 776..911
FT /note="B12-binding"
FT /evidence="ECO:0000259|PROSITE:PS51332"
FT DOMAIN 927..1266
FT /note="AdoMet activation"
FT /evidence="ECO:0000259|PROSITE:PS50974"
FT COILED 903..930
FT /evidence="ECO:0000256|SAM:Coils"
FT BINDING 260
FT /ligand="Zn(2+)"
FT /ligand_id="ChEBI:CHEBI:29105"
FT /evidence="ECO:0000256|PIRSR:PIRSR000381-1,
FT ECO:0000256|PROSITE-ProRule:PRU00333"
FT BINDING 323
FT /ligand="Zn(2+)"
FT /ligand_id="ChEBI:CHEBI:29105"
FT /evidence="ECO:0000256|PIRSR:PIRSR000381-1,
FT ECO:0000256|PROSITE-ProRule:PRU00333"
FT BINDING 324
FT /ligand="Zn(2+)"
FT /ligand_id="ChEBI:CHEBI:29105"
FT /evidence="ECO:0000256|PIRSR:PIRSR000381-1,
FT ECO:0000256|PROSITE-ProRule:PRU00333"
FT BINDING 709
FT /ligand="methylcob(III)alamin"
FT /ligand_id="ChEBI:CHEBI:28115"
FT /evidence="ECO:0000256|PIRSR:PIRSR000381-2"
FT BINDING 786..790
FT /ligand="methylcob(III)alamin"
FT /ligand_id="ChEBI:CHEBI:28115"
FT /evidence="ECO:0000256|PIRSR:PIRSR000381-2"
FT BINDING 789
FT /ligand="methylcob(III)alamin"
FT /ligand_id="ChEBI:CHEBI:28115"
FT /ligand_part="Co"
FT /ligand_part_id="ChEBI:CHEBI:27638"
FT /note="axial binding residue"
FT /evidence="ECO:0000256|PIRSR:PIRSR000381-1"
FT BINDING 834
FT /ligand="methylcob(III)alamin"
FT /ligand_id="ChEBI:CHEBI:28115"
FT /evidence="ECO:0000256|PIRSR:PIRSR000381-2"
FT BINDING 838
FT /ligand="methylcob(III)alamin"
FT /ligand_id="ChEBI:CHEBI:28115"
FT /evidence="ECO:0000256|PIRSR:PIRSR000381-2"
FT BINDING 890
FT /ligand="methylcob(III)alamin"
FT /ligand_id="ChEBI:CHEBI:28115"
FT /evidence="ECO:0000256|PIRSR:PIRSR000381-2"
FT BINDING 977
FT /ligand="S-adenosyl-L-methionine"
FT /ligand_id="ChEBI:CHEBI:59789"
FT /evidence="ECO:0000256|PIRSR:PIRSR000381-2"
FT BINDING 1173
FT /ligand="S-adenosyl-L-methionine"
FT /ligand_id="ChEBI:CHEBI:59789"
FT /evidence="ECO:0000256|PIRSR:PIRSR000381-2"
FT BINDING 1228..1229
FT /ligand="S-adenosyl-L-methionine"
FT /ligand_id="ChEBI:CHEBI:59789"
FT /evidence="ECO:0000256|PIRSR:PIRSR000381-2"
SQ SEQUENCE 1268 AA; 140241 MW; 2937BF417F1E3E0F CRC64;
MAPAASIPAD MAQRGEQIKA ELDAILQQRI MFLDGAMGTL IQTLKLEEEN FRGEEFKSHP
KPLQGNNDVL VLTMPDDIVE LHKRYLRAGA DIVETNTFNA NVISQADYAM EHLVERLNIE
AARVARRACD EIQAEGLGKK YVAGAVGPTN RTLSISPSVE QPELRNITFP ELVKAYSQQI
RALIEGGVDI LLVETIFDTA NAKAALFAID ALVEEGYPRL PLLISGTITD RSGRTLSGQT
PDAFTVSVSH ANPLALGLNC ALGAEDMRPH LEEIAKATDA YIICYPNAGL PNAMGGYDET
PEITGSHVEA FARDGLLNIV GGCCGTMPEH IASIVQKCSK FSPRPRPPKP HPNEMLLCGL
ETFLIGENTN FVNIGERCNV AGSARFCRLI KENKYDDALA VAKSQVENGA QVIDINMDDG
MLDGIKAMTT FCNLIASEPD ISRVPLCIDS SNFDVVKAGL ECVQGKCIVN SISLKEGVDD
FKNKASIIKR YGAAVVVMAF DEDGQAADLD GKIRICQRSY RILVEEVGFN PNDIIFDPNI
LTIGTGIAEH DNYGVNFIKC IRPIRESCPG AHISGGVSNL SFAFRGMNAV RESMHSVFLY
HAIKEGMDFG IVNAGVMPIY TEIDPKLVKL CEDLILNRDP DATEKMLAFA QSMTAEVKKD
EKVDEWRSLP VEKRLEHSLV KGIDKFVVED TEEARLNTTL YPKPLNVIEG PLMAGMSIVG
DLFGAGKMFL PQVIKSARVM KRAVAHLIPF MEAERDAAFR EQGIDPNTAD VSDMYNGTMV
IATVKGDVHD IGKNIVAVVL GCNNYKVVDL GVMVPANKIL DACREHKADV LGLSGLITPS
LDEMIFVAKE MQRTGLDIPL LIGGATTSKM HTAVKIAPKY QQPVIHVLDA SRSVVTVSSV
LDKKNREEYI EDIKDEYDEI REEYLDSLAD RTYVSLADAR ERRCVIDWAA EAPAKPNMTG
LKVIEDVDLE RVVKYIDWKP FFEVWQLRGK YPNRNYPKIF DDAHVGEEAQ RVFADGQALL
RRIIDEKLIR GKGVFGIFPA NTVNHDDIEI YADDTRTEPT ATLFGLRQQA EKMDKSDAYF
CQSDFVAPKE SGIPDYVGLF AVNCGIGADE LANKFLADHD DYNNIMVKAL ADRLAEAFAE
MLHEDVRREY WGYAKDESFN SRELHQLKYD GIRPAPGYPT QPDHTEKATY WKLLDAEARA
AMSLTESFSM MPAASVSGLF FAHPKSEYFA VGKITREQVV DYAERKGQEV ETVERWLAPI
LAYDPDEE
//
