ID Q818K0_BACCR Unreviewed; 1133 AA.
AC Q818K0;
DT 01-JUN-2003, integrated into UniProtKB/TrEMBL.
DT 01-JUN-2003, sequence version 1.
DT 27-MAR-2024, entry version 148.
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=BC_4250 {ECO:0000313|EMBL:AAP11165.1};
OS Bacillus cereus (strain ATCC 14579 / DSM 31 / CCUG 7414 / JCM 2152 / NBRC
OS 15305 / NCIMB 9373 / NCTC 2599 / NRRL B-3711).
OC Bacteria; Bacillota; Bacilli; Bacillales; Bacillaceae; Bacillus;
OC Bacillus cereus group.
OX NCBI_TaxID=226900 {ECO:0000313|EMBL:AAP11165.1, ECO:0000313|Proteomes:UP000001417};
RN [1] {ECO:0000313|EMBL:AAP11165.1, ECO:0000313|Proteomes:UP000001417}
RP NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC STRAIN=ATCC 14579 / DSM 31 / CCUG 7414 / JCM 2152 / NBRC 15305 / NCIMB
RC 9373 / NCTC 2599 / NRRL B-3711 {ECO:0000313|Proteomes:UP000001417};
RX PubMed=12721630; DOI=10.1038/nature01582;
RA Ivanova N., Sorokin A., Anderson I., Galleron N., Candelon B., Kapatral V.,
RA Bhattacharyya A., Reznik G., Mikhailova N., Lapidus A., Chu L., Mazur M.,
RA Goltsman E., Larsen N., D'Souza M., Walunas T., Grechkin Y., Pusch G.,
RA Haselkorn R., Fonstein M., Ehrlich S.D., Overbeek R., Kyrpides N.;
RT "Genome sequence of Bacillus cereus and comparative analysis with Bacillus
RT anthracis.";
RL Nature 423:87-91(2003).
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; AE016877; AAP11165.1; -; Genomic_DNA.
DR RefSeq; NP_833964.1; NC_004722.1.
DR AlphaFoldDB; Q818K0; -.
DR KEGG; bce:BC4250; -.
DR PATRIC; fig|226900.8.peg.4394; -.
DR HOGENOM; CLU_004914_4_0_9; -.
DR UniPathway; UPA00051; UER00081.
DR Proteomes; UP000001417; Chromosome.
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 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; 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:UP000001417};
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..301
FT /note="Hcy-binding"
FT /evidence="ECO:0000259|PROSITE:PS50970"
FT DOMAIN 331..586
FT /note="Pterin-binding"
FT /evidence="ECO:0000259|PROSITE:PS50972"
FT DOMAIN 612..706
FT /note="B12-binding N-terminal"
FT /evidence="ECO:0000259|PROSITE:PS51337"
FT DOMAIN 706..841
FT /note="B12-binding"
FT /evidence="ECO:0000259|PROSITE:PS51332"
FT DOMAIN 839..1133
FT /note="AdoMet activation"
FT /evidence="ECO:0000259|PROSITE:PS50974"
FT BINDING 223
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 286
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 287
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 716..720
FT /ligand="methylcob(III)alamin"
FT /ligand_id="ChEBI:CHEBI:28115"
FT /evidence="ECO:0000256|PIRSR:PIRSR000381-2"
FT BINDING 719
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 764
FT /ligand="methylcob(III)alamin"
FT /ligand_id="ChEBI:CHEBI:28115"
FT /evidence="ECO:0000256|PIRSR:PIRSR000381-2"
FT BINDING 820
FT /ligand="methylcob(III)alamin"
FT /ligand_id="ChEBI:CHEBI:28115"
FT /evidence="ECO:0000256|PIRSR:PIRSR000381-2"
FT BINDING 1075
FT /ligand="S-adenosyl-L-methionine"
FT /ligand_id="ChEBI:CHEBI:59789"
FT /evidence="ECO:0000256|PIRSR:PIRSR000381-2"
FT BINDING 1129..1130
FT /ligand="S-adenosyl-L-methionine"
FT /ligand_id="ChEBI:CHEBI:59789"
FT /evidence="ECO:0000256|PIRSR:PIRSR000381-2"
SQ SEQUENCE 1133 AA; 125963 MW; 10F28DF09227F283 CRC64;
MMKCIEEKLK NSILILDGAM GTMIQQEDLT AEDFGGEEYE GCNEYLVETR PDVILKIHKA
YIEAGADIIE TNTFGATNIV LSDYDLSHLD EELNEEAALL AKQAVKESGK EVYVAGAMGP
TTKAISVTGG VTFEELIEAY TRQARGLLKG AVDVVLVETS QDMRNVKAAY IGIQAAFEEL
KKTVPIMISG TIEPMGTTLA GQTIEAFYLS VEHMKPLSVG LNCATGPEFM RDHIRSLSDL
SECYISCYPN AGLPDEDGHY HESPSSLAEK VKRFAEEGWV NIIGGCCGTT PEHIKAMKSA
LASLRPRDHH EREGHGISGL EALQYDESMR PLFVGERTNV IGSRKFKRLV AEGKFEEAAE
VARAQVKKNA HIIDICMADP DRDEIEDMEN FLAEVTKVLK VPIMIDSTDE NVMERALTYI
QGKAVINSIN LEDGEERFKK VTPLLQKYGA AIVVGTIDED GMAVSAERKI EIAKRSYELL
TKKYGIRPSD IIFDALVFPV GTGDEEYIGS AAATIEGIRL IKEALPECLT ILGVSNISFG
LPPAGREVLN SVFLYHATKA GLDYAIVNTE KLERYASIPE EEKRLADALL FETTKETLEE
FTNFYRVAKK KDVVVQETLT LDERLANYIV EGTKQGLHED LSLALEEGRK PLDIINGPLM
TGMDEVGRLF NNNELIVAEV LQSAESMKAA VSYLEPHMES SDSAKKGKVL LATVKGDVHD
IGKNLVEIIL ANNGYEIINL GINVRSDRIV QEVQEKKPDI IGLSGLLVKS AQQMVTTAED
LKAANIDVPI VVGGAALTRK FTDNRISPSY KGLVCYASDA MTGLDIINKL QKEEEREKMK
QDKKERHLHI VKKEEKKVEI PAVIEPLPKS EVMVPDSTKR IVLRDVPALH LAPFLNRQML
LGHHLGLKGN VKKLLKEGDK RAHELNDLID ELLQEGQSWL KPKAVYQFFP AQSDGQNIVI
YDPEDHTRVI ERFTFPRQGK APYRTLGDYL RPIGDEMDYV AFLSVTVGEG VRDIAEELKA
KGDYLRSHAI QSLALELAEG LAEKTHMLIR DRWGIPDSPE LTMEERFRTK YRGIRVSFGY
PACPELADQE KLFRLIHPEE IGISLTEGFM MEPEASVTAM VFSHPEARYF SVL
//
