ID A9BAF6_PROM4 Unreviewed; 1191 AA.
AC A9BAF6;
DT 15-JAN-2008, integrated into UniProtKB/TrEMBL.
DT 15-JAN-2008, sequence version 1.
DT 27-MAR-2024, entry version 113.
DE RecName: Full=Methionine synthase {ECO:0000256|ARBA:ARBA00013998, 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|ARBA:ARBA00031040, ECO:0000256|PIRNR:PIRNR000381};
GN Name=metH {ECO:0000313|EMBL:ABX08818.1};
GN OrderedLocusNames=P9211_08871 {ECO:0000313|EMBL:ABX08818.1};
OS Prochlorococcus marinus (strain MIT 9211).
OC Bacteria; Cyanobacteriota; Cyanophyceae; Synechococcales;
OC Prochlorococcaceae; Prochlorococcus.
OX NCBI_TaxID=93059 {ECO:0000313|EMBL:ABX08818.1, ECO:0000313|Proteomes:UP000000788};
RN [1] {ECO:0000313|EMBL:ABX08818.1, ECO:0000313|Proteomes:UP000000788}
RP NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC STRAIN=MIT 9211 {ECO:0000313|Proteomes:UP000000788};
RX PubMed=18159947; DOI=10.1371/journal.pgen.0030231;
RA Kettler G.C., Martiny A.C., Huang K., Zucker J., Coleman M.L., Rodrigue S.,
RA Chen F., Lapidus A., Ferriera S., Johnson J., Steglich C., Church G.M.,
RA Richardson P., Chisholm S.W.;
RT "Patterns and implications of gene gain and loss in the evolution of
RT Prochlorococcus.";
RL PLoS Genet. 3:2515-2528(2007).
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|ARBA:ARBA00025552,
CC 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|ARBA:ARBA00001700,
CC 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; CP000878; ABX08818.1; -; Genomic_DNA.
DR RefSeq; WP_012195440.1; NC_009976.1.
DR AlphaFoldDB; A9BAF6; -.
DR STRING; 93059.P9211_08871; -.
DR KEGG; pmj:P9211_08871; -.
DR eggNOG; COG0646; Bacteria.
DR eggNOG; COG1410; Bacteria.
DR HOGENOM; CLU_004914_4_0_3; -.
DR OrthoDB; 9803687at2; -.
DR UniPathway; UPA00051; UER00081.
DR Proteomes; UP000000788; Chromosome.
DR GO; GO:0031419; F:cobalamin binding; IEA:UniProtKB-UniRule.
DR GO; GO:0008705; F:methionine synthase activity; IEA:UniProtKB-UniRule.
DR GO; GO:0008270; F:zinc ion binding; IEA:UniProtKB-UniRule.
DR GO; GO:0032259; P:methylation; IEA:UniProtKB-KW.
DR GO; GO:0042558; P:pteridine-containing compound metabolic process; IEA:InterPro.
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; 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 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:UP000000788};
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 2..306
FT /note="Hcy-binding"
FT /evidence="ECO:0000259|PROSITE:PS50970"
FT DOMAIN 344..603
FT /note="Pterin-binding"
FT /evidence="ECO:0000259|PROSITE:PS50972"
FT DOMAIN 635..728
FT /note="B12-binding N-terminal"
FT /evidence="ECO:0000259|PROSITE:PS51337"
FT DOMAIN 730..865
FT /note="B12-binding"
FT /evidence="ECO:0000259|PROSITE:PS51332"
FT DOMAIN 903..1191
FT /note="AdoMet activation"
FT /evidence="ECO:0000259|PROSITE:PS50974"
FT BINDING 225
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 291
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 292
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 740..744
FT /ligand="methylcob(III)alamin"
FT /ligand_id="ChEBI:CHEBI:28115"
FT /evidence="ECO:0000256|PIRSR:PIRSR000381-2"
FT BINDING 743
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 788
FT /ligand="methylcob(III)alamin"
FT /ligand_id="ChEBI:CHEBI:28115"
FT /evidence="ECO:0000256|PIRSR:PIRSR000381-2"
FT BINDING 844
FT /ligand="methylcob(III)alamin"
FT /ligand_id="ChEBI:CHEBI:28115"
FT /evidence="ECO:0000256|PIRSR:PIRSR000381-2"
FT BINDING 951
FT /ligand="S-adenosyl-L-methionine"
FT /ligand_id="ChEBI:CHEBI:59789"
FT /evidence="ECO:0000256|PIRSR:PIRSR000381-2"
FT BINDING 1134
FT /ligand="S-adenosyl-L-methionine"
FT /ligand_id="ChEBI:CHEBI:59789"
FT /evidence="ECO:0000256|PIRSR:PIRSR000381-2"
FT BINDING 1188..1189
FT /ligand="S-adenosyl-L-methionine"
FT /ligand_id="ChEBI:CHEBI:59789"
FT /evidence="ECO:0000256|PIRSR:PIRSR000381-2"
SQ SEQUENCE 1191 AA; 132032 MW; 70BF35D686176A61 CRC64;
MDFINHLKKR NTILVFDGGM GTALQLQELS KEDFGGSQFE GCNEYLLISN PKSVEKVHRS
YLEVGCDVIE TNTFGATSVV LAEYGLENKA YQLNLAASKM AKTLAKEYST INKPRYAAGS
IGPTTKLPTL GHIDFDDLTN SYQEQVEALI TGGIDLVLVE TCQDVLQIKS ALLAISLAEK
SLGIKIPVMV SITMETTGTM LIGTEISAAL TILEPFNIDI LGLNCATGPE EMKSHIQYLS
SHSPFITSCI PNAGLPENIG GKAHYRLTPI ELKMQLMHFI KDLGVKVIGG CCGTTPEHIK
GLTQLVEEIT NSNDQNLPSI KKIATQPSAS SIYEKISYQQ DNSFLIVGER LNASGSKKVR
ELLNKDDWDG LVSLAKGQLK ENAHILDVNV DYVGRDGVAD MSRLVSKLVT NVNIPLMLDS
TDYEKMESGL KKAGGKCILN STNFEDGPDR FFQVLQLCKS HGSSVVIGTI DEEGMARTAS
KKLDITKRSY KEATCFGLKD SDIFFDPLVL PITTGIEDDR LNAKETILAI KNIKSLYPSV
HLILGISNVS FGLNPAARVT LNSVFLNECI NSGLDSAIIS PSKILPLSKV SEDNLKICLD
LIYDKRKYRD HICIYDPLTQ LTKAFEGVSA KSKSSSDDLS KLPIEKRLKS HIIEGEKEKL
RENLLIALEG YKPLHIVNTF LLDGMKVVGE LFGSGQMQLP FVLQSAETMK YAVSILEPFM
EKTSDSKSSK GKFIIATVKG DVHDIGKNLV DIILTNNGYE VFNLGIKQDV NSIIKAQEGI
QADCIAMSGL LVKSTAFMKD NLQALNEANI QVPVILGGAA LTPRFVNTDC SQVYNGMVIY
GKDAFTDLRF MDAYMEAKIN NRWDNKLGFL DGNPDNLSIP NPSASKNPDY INDNKTIKIT
TNSLKTKGTL QANTSRSNTI LKEKPIVPPF KGNRILNSQQ LDLSQYSFYL DRNALFSGQW
QFKKKKEQSR EDYEQDLIDT AEPILESWIT RIQEQNLISP SLVYGYFPCA RVGNSLKIYS
LTSHQYLGTF TFPRQRSGNK LCISDYFNDL ENDRPIDYLP MQAVTMGEEA SMFAHKLYKE
DKYTDYLFFH GLIVQLAEAL AEYSHSIIRT ECGFAGLEPK NIKDILAQRY RGCRYSFGYP
ACPNVGDSRL QLKWLEGSRI GLSMDDSDQL HPEQSTTAII ALHSQAKYFS A
//
