ID B8HR05_CYAP4 Unreviewed; 1212 AA.
AC B8HR05;
DT 03-MAR-2009, integrated into UniProtKB/TrEMBL.
DT 03-MAR-2009, sequence version 1.
DT 27-MAR-2024, entry version 102.
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 OrderedLocusNames=Cyan7425_3503 {ECO:0000313|EMBL:ACL45826.1};
OS Cyanothece sp. (strain PCC 7425 / ATCC 29141).
OC Bacteria; Cyanobacteriota; Cyanophyceae; Gomontiellales; Cyanothecaceae;
OC Cyanothece.
OX NCBI_TaxID=395961 {ECO:0000313|EMBL:ACL45826.1};
RN [1] {ECO:0000313|EMBL:ACL45826.1}
RP NUCLEOTIDE SEQUENCE.
RC STRAIN=PCC 7425 {ECO:0000313|EMBL:ACL45826.1};
RG US DOE Joint Genome Institute;
RA Lucas S., Copeland A., Lapidus A., Glavina del Rio T., Dalin E., Tice H.,
RA Bruce D., Goodwin L., Pitluck S., Sims D., Meineke L., Brettin T.,
RA Detter J.C., Han C., Larimer F., Land M., Hauser L., Kyrpides N.,
RA Ovchinnikova G., Liberton M., Stoeckel J., Banerjee A., Singh A., Page L.,
RA Sato H., Zhao L., Sherman L., Pakrasi H., Richardson P.;
RT "Complete sequence of chromosome Cyanothece sp. PCC 7425.";
RL Submitted (JAN-2009) to the EMBL/GenBank/DDBJ databases.
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; CP001344; ACL45826.1; -; Genomic_DNA.
DR AlphaFoldDB; B8HR05; -.
DR STRING; 395961.Cyan7425_3503; -.
DR KEGG; cyn:Cyan7425_3503; -.
DR eggNOG; COG0646; Bacteria.
DR eggNOG; COG1410; Bacteria.
DR HOGENOM; CLU_004914_4_0_3; -.
DR OrthoDB; 9803687at2; -.
DR UniPathway; UPA00051; UER00081.
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; 2.
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}; 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 5..309
FT /note="Hcy-binding"
FT /evidence="ECO:0000259|PROSITE:PS50970"
FT DOMAIN 362..621
FT /note="Pterin-binding"
FT /evidence="ECO:0000259|PROSITE:PS50972"
FT DOMAIN 653..746
FT /note="B12-binding N-terminal"
FT /evidence="ECO:0000259|PROSITE:PS51337"
FT DOMAIN 749..884
FT /note="B12-binding"
FT /evidence="ECO:0000259|PROSITE:PS51332"
FT DOMAIN 915..1212
FT /note="AdoMet activation"
FT /evidence="ECO:0000259|PROSITE:PS50974"
FT BINDING 228
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 294
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 295
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 759..763
FT /ligand="methylcob(III)alamin"
FT /ligand_id="ChEBI:CHEBI:28115"
FT /evidence="ECO:0000256|PIRSR:PIRSR000381-2"
FT BINDING 762
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 807
FT /ligand="methylcob(III)alamin"
FT /ligand_id="ChEBI:CHEBI:28115"
FT /evidence="ECO:0000256|PIRSR:PIRSR000381-2"
FT BINDING 863
FT /ligand="methylcob(III)alamin"
FT /ligand_id="ChEBI:CHEBI:28115"
FT /evidence="ECO:0000256|PIRSR:PIRSR000381-2"
FT BINDING 964
FT /ligand="S-adenosyl-L-methionine"
FT /ligand_id="ChEBI:CHEBI:59789"
FT /evidence="ECO:0000256|PIRSR:PIRSR000381-2"
FT BINDING 1155
FT /ligand="S-adenosyl-L-methionine"
FT /ligand_id="ChEBI:CHEBI:59789"
FT /evidence="ECO:0000256|PIRSR:PIRSR000381-2"
FT BINDING 1209..1210
FT /ligand="S-adenosyl-L-methionine"
FT /ligand_id="ChEBI:CHEBI:59789"
FT /evidence="ECO:0000256|PIRSR:PIRSR000381-2"
SQ SEQUENCE 1212 AA; 134307 MW; D5D76A19B86758D4 CRC64;
MVNSFLARLH HPDRPVLVFD GAMGTNIQTQ NLTAEDFGGP QYEGCNEYLV HTKPEAIAKV
HRDFLAAGAD VIETDTFGSS PLVLAEYDLA DQSYYLSKTA AELAKQCAAE FSTPEKPRFV
AGSIGPGTKL PTLGHINYDQ LKAAFTVQAE GLFDGGVDLF IIETCQDVLQ IKAALNAVEA
VFEQKGERRP LMVSVTMEVQ GTMLVGTDIS GVLAILEPYP IDILGLNCAT GPDRMADHIK
YLTENAPFVV SCIPNAGLPE NIGGHAHYKL TPMELRLALH RFVEDWGVQV IGGCCGTRPA
HIQALAEIAQ SLQPKARNVR VGEQTWLNGS LHPIDTPRPT LNYTPAAASI YTAQPYEQDN
SFLIVGERLN ASGSKKVREL LNADDWDGLI AIAKAQVKEG AHVLDVNVDY VGRNGERDMH
ELVSRLVTNI TLPLMLDSTE WQKMEAGLKV AGGKCILNST NYEDGPERFF KVLELAKTYG
AGVVIGTIDE EGMARTAERK FQIAQRAYRD AVEFGLPPHE LFFDTLALPI STGIEEDREN
GKATIEAIRR IRAELPGVHF MLGVSNISFG LSPAARITLN SMFLHEAMQV GMDGAIVSAA
KILPLSKISE DHQQVCQDLI YDRRRFEGDI CIYDPLTQLT TLFEGVSAKE ARSSSSLADL
PIEERLKQHI IDGERIGLEA ALKIALETYK PLEIINTFLL DGMKVVGELF GSGQMQLPFV
LQSAETMKAA VAFLEPLMDK VEGQGDSGKG KFLIATVKGD VHDIGKNLVD IILTNNGYKV
INLGIKQPVD AIIDAYTQHQ PDCIAMSGLL VKSTAFMKEN LEVFNQRGIT VPVILGGAAL
TPKFVYEDCQ QTYNGQVIYG RDAFADLTFM DRLMPAKTQG KWSDREGFQA DLAHYNQKGR
QAIDAAEREL NPTKPEKATT TDVVDTVRSE AVELNIPRPT PPFWGSQILN PADIDLEEVF
RYLDLQALVS GQWQFRKPQG QSREEYDTFL AEKVYPILDS WQQRIIDEKL LHPQLVYGYF
PCVAEGNSVH LYDPAVIAQG LTPQTATAIV TWTFPRQKSM RRLCIADFFR PITENQFDVF
PMQAVTVGQI ATEFAQQLFA ENLYTDYLYF HGLAVQTAEA LAEWCHVRIR RELGYGDLEP
EHIRDILAQR YQGSRYSFGY PACPNVADQF KQLELLATDR IGMSIDDSEQ LYPEQSTTAI
ITYHPIAKYF SA
//
