ID METH_VIBFI Reviewed; 1226 AA.
AC Q9AJQ8;
DT 22-NOV-2005, integrated into UniProtKB/Swiss-Prot.
DT 01-JUN-2001, sequence version 1.
DT 03-APR-2013, entry version 62.
DE RecName: Full=Methionine synthase;
DE EC=2.1.1.13;
DE AltName: Full=5-methyltetrahydrofolate--homocysteine methyltransferase;
DE AltName: Full=Methionine synthase, vitamin-B12 dependent;
DE Short=MS;
GN Name=metH;
OS Vibrio fischeri.
OC Bacteria; Proteobacteria; Gammaproteobacteria; Vibrionales;
OC Vibrionaceae; Aliivibrio.
OX NCBI_TaxID=668;
RN [1]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RC STRAIN=ATCC 7744 / NCIMB 1281;
RX PubMed=11250084; DOI=10.1016/S0378-1119(01)00339-0;
RA Kasai S., Yamazaki T.;
RT "Identification of the cobalamin-dependent methionine synthase gene,
RT metH, in Vibrio fischeri ATCC 7744 by sequencing using genomic DNA as
RT a template.";
RL Gene 264:281-288(2001).
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 (By similarity).
CC -!- CATALYTIC ACTIVITY: 5-methyltetrahydrofolate + L-homocysteine =
CC tetrahydrofolate + L-methionine.
CC -!- COFACTOR: Cobalamin (By similarity).
CC -!- COFACTOR: Binds 1 zinc ion per subunit (By similarity).
CC -!- PATHWAY: Amino-acid biosynthesis; L-methionine biosynthesis via de
CC novo pathway; L-methionine from L-homocysteine (MetH route): step
CC 1/1.
CC -!- DOMAIN: Modular enzyme with four functionally distinct domains.
CC The isolated Hcy-binding domain catalyzes methyl transfer from
CC free methylcobalamin to homocysteine. The Hcy-binding domain in
CC association with the pterin-binding domain catalyzes the
CC methylation of cob(I)alamin by methyltetrahydrofolate and the
CC methylation of homocysteine. The B12-binding domain binds the
CC cofactor. The AdoMet activation domain binds S-adenosyl-L-
CC methionine. Under aerobic conditions cob(I)alamin can be converted
CC to inactive cob(II)alamin. Reductive methylation by S-adenosyl-L-
CC methionine and flavodoxin regenerates methylcobalamin (By
CC similarity).
CC -!- MISCELLANEOUS: L-homocysteine is bound via the zinc atom (By
CC similarity).
CC -!- SIMILARITY: Belongs to the vitamin-B12 dependent methionine
CC synthase family.
CC -!- SIMILARITY: Contains 1 AdoMet activation domain.
CC -!- SIMILARITY: Contains 1 B12-binding domain.
CC -!- SIMILARITY: Contains 1 B12-binding N-terminal domain.
CC -!- SIMILARITY: Contains 1 Hcy-binding domain.
CC -!- SIMILARITY: Contains 1 pterin-binding domain.
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DR EMBL; AB039955; BAB39355.1; -; Genomic_DNA.
DR ProteinModelPortal; Q9AJQ8; -.
DR SMR; Q9AJQ8; 655-1225.
DR PRIDE; Q9AJQ8; -.
DR UniPathway; UPA00051; UER00081.
DR GO; GO:0005622; C:intracellular; IEA:InterPro.
DR GO; GO:0031419; F:cobalamin binding; IEA:UniProtKB-KW.
DR GO; GO:0008898; F:homocysteine S-methyltransferase activity; IEA:InterPro.
DR GO; GO:0008705; F:methionine synthase activity; IEA:EC.
DR GO; GO:0008270; F:zinc ion binding; IEA:InterPro.
DR GO; GO:0042558; P:pteridine-containing compound metabolic process; IEA:InterPro.
DR Gene3D; 1.10.1240.10; -; 1.
DR Gene3D; 3.10.196.10; -; 1.
DR Gene3D; 3.20.20.20; -; 1.
DR Gene3D; 3.20.20.330; -; 1.
DR Gene3D; 3.40.50.280; -; 1.
DR InterPro; IPR003759; Cbl-bd_cap.
DR InterPro; IPR006158; Cobalamin-bd.
DR InterPro; IPR011005; Dihydropteroate_synth-like.
DR InterPro; IPR011822; MetH.
DR InterPro; IPR000489; Pterin-binding.
DR InterPro; IPR003726; S_MeTrfase.
DR InterPro; IPR004223; VitB12-dep_Met_synth_activ_dom.
DR PANTHER; PTHR21091:SF9; PTHR21091:SF9; 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; Cbl-bd; 1.
DR SUPFAM; SSF51717; DHP_synth_like; 1.
DR SUPFAM; SSF56507; Met_synth_B12; 1.
DR SUPFAM; SSF47644; Met_synth_Cbl-bd; 1.
DR SUPFAM; SSF82282; S_methyl_trans; 1.
DR TIGRFAMs; TIGR02082; metH; 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; Cobalamin; Cobalt; Metal-binding;
KW Methionine biosynthesis; Methyltransferase; Repeat;
KW S-adenosyl-L-methionine; Transferase; Zinc.
FT CHAIN 1 1226 Methionine synthase.
FT /FTId=PRO_0000204540.
FT DOMAIN 7 327 Hcy-binding.
FT DOMAIN 358 619 Pterin-binding.
FT DOMAIN 652 746 B12-binding N-terminal.
FT DOMAIN 748 883 B12-binding.
FT DOMAIN 899 1226 AdoMet activation.
FT REGION 836 837 Cobalamin-binding (By similarity).
FT REGION 1192 1193 S-adenosyl-L-methionine binding (By
FT similarity).
FT METAL 249 249 Zinc (By similarity).
FT METAL 312 312 Zinc (By similarity).
FT METAL 313 313 Zinc (By similarity).
FT METAL 761 761 Cobalt (cobalamin axial ligand) (By
FT similarity).
FT BINDING 806 806 Cobalamin (By similarity).
FT BINDING 949 949 S-adenosyl-L-methionine (By similarity).
FT BINDING 1137 1137 S-adenosyl-L-methionine; via carbonyl
FT oxygen (By similarity).
FT BINDING 1141 1141 Cobalamin; via carbonyl oxygen (By
FT similarity).
SQ SEQUENCE 1226 AA; 136266 MW; AF210E43E119E50C CRC64;
MAGSNIKVQI EKQLSERILL IDGGMGTMIQ GYKFEEKDYR GGRFNQWHCD LKGNNDLLVL
SQPQIIRDIH EAYLEAGADI LETNTFNATT IAMADYDMES LSEEINFEAA KLAREVADKW
TEKTPNKPRY VAGVLGPTNR TCSISPDVND PGFRNVSFDE LVEAYSESTR ALIRGGSDLI
LIETIFDTLN AKACSFAVES VFEELGITLP VMISGTITDA SGRTLSGQTT EAFYNALRHV
KPISFGLNCA LGPDELREYV SELSRISECY VSAHPNAGLP NAFGEYDLSP EDMAEHVAEW
ASSGFLNLIG GCCGTTPEHI RQMALVVEGV KPRQLPELPV ACRLSGLEPL TIEKDSLFIN
VGERTNVTGS ARFKRLIKEE LYDEALSVAQ EQVENGAQII DINMDEGMLD AEACMVRFLN
LCASEPEISK VPVMVDSSKW EVIEAGLKCI QGKGIVNSIS LKEGKEKFVH QAKLIRRYGA
AVIVMAFDEV GQADTRERKI EICTNAYNIL VDEVGFPPED IIFDPNIFAV ATGIDEHNNY
AVDFIEAVGD IKRTLPHAMI SGGVSNVSFS FRGNNYVREA IHAVFLYHCF KNGMDMGIVN
AGQLEIYDNV PEDLREAVED VVLNRRDDST ERLLDIATEY LERAVGKVED KSALEWRDWP
VEKRLEHSLV KGITEFIVED TEEARINAER PIEVIEGPLM DGMNVVGDLF GEGKMFLPQV
VKSARVMKQA VAHLEPFINA SKEVGATNGK ILLATVKGDV HDIGKNIVGV VLQCNNYEII
DLGVMVSCET ILKVAKEENV DIIGLSGLIT PSLDEMVHVA KEMERQGFDL PLLIGGATTS
KAHTAVKIEQ NYSQPVVYVN NASRAVGVCT SLLSNELKPS FVEKLDIDYE RVREQHSRKQ
PRTKPVTLEV ARANKVAIDW ASYTPPVPLK PGVHIFDNFD VSTLRNYIDW TPFFMTWSLV
GKYPKILEHE EVGEEAKRLF KDANDLLDRV EKEGLLKARG MCALFPASSV GDDIEVYTDE
SRTTVAKVLH NLRQQTEKPK GFNYCLSDYI APKESGKNDW IGGFAVTGGI GERELADEYK
ANGDDYNAIM IQAVADRLAE AFAEYLHEKV RKEIWGYSPN ETLSNDDLIR EKYQGIRPAP
GYPACPEHTE KGALWELMNV EESIGMSLTS SYAMWPGASV SGMYFSHPDS RYFAIAQIQQ
DQAESYADRK GWNMLEAEKW LGPNLN
//
