METH_PSEPU
ID METH_PSEPU Reviewed; 607 AA.
AC O33465;
DT 15-JUL-1998, integrated into UniProtKB/Swiss-Prot.
DT 01-JAN-1998, sequence version 1.
DT 03-AUG-2022, entry version 84.
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;
DE Flags: Fragment;
GN Name=metH;
OS Pseudomonas putida (Arthrobacter siderocapsulatus).
OC Bacteria; Proteobacteria; Gammaproteobacteria; Pseudomonadales;
OC Pseudomonadaceae; Pseudomonas.
OX NCBI_TaxID=303;
RN [1]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RC STRAIN=P8;
RX PubMed=9361416; DOI=10.1128/aem.63.11.4292-4297.1997;
RA Holtwick R., Meinhardt F., Keweloh H.;
RT "Cis-trans isomerization of unsaturated fatty acids: cloning and sequencing
RT of the cti gene from Pseudomonas putida P8.";
RL Appl. Environ. Microbiol. 63:4292-4297(1997).
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). {ECO:0000250}.
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 -!- COFACTOR:
CC Name=methylcob(III)alamin; Xref=ChEBI:CHEBI:28115;
CC Evidence={ECO:0000250};
CC -!- COFACTOR:
CC Name=Zn(2+); Xref=ChEBI:CHEBI:29105; Evidence={ECO:0000305};
CC Note=Binds 1 zinc ion per subunit. {ECO:0000305};
CC -!- PATHWAY: Amino-acid biosynthesis; L-methionine biosynthesis via de novo
CC pathway; L-methionine from L-homocysteine (MetH route): step 1/1.
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 (By similarity). {ECO:0000250}.
CC -!- MISCELLANEOUS: L-homocysteine is bound via the zinc atom.
CC {ECO:0000250}.
CC -!- SIMILARITY: Belongs to the vitamin-B12 dependent methionine synthase
CC family. {ECO:0000305}.
CC -!- CAUTION: Ser-314 is present instead of the conserved Cys which is
CC expected to be a zinc-binding residue. {ECO:0000305}.
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DR EMBL; AJ000978; CAA04437.1; -; Genomic_DNA.
DR AlphaFoldDB; O33465; -.
DR SMR; O33465; -.
DR STRING; 1240350.AMZE01000004_gene2420; -.
DR PRIDE; O33465; -.
DR eggNOG; COG0646; Bacteria.
DR eggNOG; COG1410; Bacteria.
DR UniPathway; UPA00051; UER00081.
DR GO; GO:0031419; F:cobalamin binding; IEA:UniProtKB-KW.
DR GO; GO:0046872; F:metal ion binding; IEA:UniProtKB-KW.
DR GO; GO:0008705; F:methionine synthase activity; IEA:UniProtKB-EC.
DR GO; GO:0032259; P:methylation; IEA:UniProtKB-KW.
DR GO; GO:0042558; P:pteridine-containing compound metabolic process; IEA:InterPro.
DR Gene3D; 3.20.20.20; -; 1.
DR Gene3D; 3.20.20.330; -; 1.
DR InterPro; IPR011005; Dihydropteroate_synth-like.
DR InterPro; IPR003726; HCY_dom.
DR InterPro; IPR036589; HCY_dom_sf.
DR InterPro; IPR000489; Pterin-binding_dom.
DR Pfam; PF00809; Pterin_bind; 1.
DR Pfam; PF02574; S-methyl_trans; 1.
DR SUPFAM; SSF51717; SSF51717; 1.
DR SUPFAM; SSF82282; SSF82282; 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; S-adenosyl-L-methionine;
KW Transferase; Zinc.
FT CHAIN 1..>607
FT /note="Methionine synthase"
FT /id="PRO_0000204535"
FT DOMAIN 8..328
FT /note="Hcy-binding"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00333"
FT DOMAIN 359..>607
FT /note="Pterin-binding"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00334"
FT BINDING 250
FT /ligand="Zn(2+)"
FT /ligand_id="ChEBI:CHEBI:29105"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00333"
FT BINDING 313
FT /ligand="Zn(2+)"
FT /ligand_id="ChEBI:CHEBI:29105"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00333"
FT NON_TER 607
SQ SEQUENCE 607 AA; 65840 MW; BB7743CC28A922B3 CRC64;
MSDRSARLQA LQNALKERIL ILDGGMGTMI QSYRLEEHDY RGTRFADWPS DVKGNNDLLL
LSRPDVIAAI EKAYLDAGAD ILETNTFNAT QISQADYGME SLVYELNVEG ARIARQVADA
KTLETPDKPR FVAGVLGPTS RTCSISPDVN DPGYRNVTFD ELVENYIEAT RGLIEGGADL
ILIETIFDTL NAKAAIFAVQ QVFEEDAVEL PIMISGTITD ASGRTLSGQT TEAFWNSVRH
AKPISVGLNC ALGAKDLRPY LEELSTKADT HVSAHPNAGL PNAFGEYDET PAEMAAVVEE
FAASGFLNII GGCSGTTPGH IQAIAEAVAK YKPREIPEIA KACRLSGLEP FTIDGQSLFV
NVGERTNITG SAKFARLIRE ENYTEALEVA LQQVEAGAQV IDINMDEGML DSQAAMVRFL
NMIAGEPDIS RVPIMIDSSK GEVIEAGLKC IQGKGIVNSI SMKEGVEQFK HHARLCKRYG
AAVVVMAFDE VGQADTAARK KEICKRSYDI LVNEVGFPPE DIIFDPNIFA VATGIEEHNN
YAVDFIEACA YIRDHLPHAL TSGGVSNVSF SFRGNNPVRE AIHSVFLFHA ISNGLTMGIV
NAGLLEI
