Q9AJQ8 (METH_VIBFI) Reviewed, UniProtKB/Swiss-Prot

Names and origin

Protein names

Recommended name:
Methionine synthase
EC=2.1.1.13

Alternative name(s):
5-methyltetrahydrofolate--homocysteine methyltransferase
Methionine synthase, vitamin-B12 dependent
Short name=MS

Gene names

Name:

metH

Organism

Vibrio fischeri

Taxonomic identifier

668 [NCBI]

Taxonomic lineage

cellular organisms › Bacteria › Proteobacteria › Gammaproteobacteria › Vibrionales › Vibrionaceae › Aliivibrio

Protein attributes

Sequence length	1226 AA.
Sequence status	Complete.
Protein existence	Inferred from homology

General annotation (Comments)

Function	Catalyzes the transfer of a methyl group from methyl-cobalamin to homocysteine, yielding enzyme-bound cob(I)alamin and methionine. Subsequently, remethylates the cofactor using methyltetrahydrofolate By similarity.
Catalytic activity	5-methyltetrahydrofolate + L-homocysteine = tetrahydrofolate + L-methionine.
Cofactor	Cobalamin By similarity. Binds 1 zinc ion per subunit By similarity.
Pathway	Amino-acid biosynthesis; L-methionine biosynthesis via de novo pathway; L-methionine from L-homocysteine (MetH route): step 1/1.
Domain	Modular enzyme with four functionally distinct domains. The isolated Hcy-binding domain catalyzes methyl transfer from free methylcobalamin to homocysteine. The Hcy-binding domain in association with the pterin-binding domain catalyzes the methylation of cob(I)alamin by methyltetrahydrofolate and the methylation of homocysteine. The B12-binding domain binds the cofactor. The AdoMet activation domain binds S-adenosyl-L-methionine. Under aerobic conditions cob(I)alamin can be converted to inactive cob(II)alamin. Reductive methylation by S-adenosyl-L-methionine and flavodoxin regenerates methylcobalamin By similarity.
Miscellaneous	L-homocysteine is bound via the zinc atom By similarity.
Sequence similarities	Belongs to the vitamin-B12 dependent methionine synthase family. Contains 1 AdoMet activation domain. Contains 1 B12-binding domain. Contains 1 B12-binding N-terminal domain. Contains 1 Hcy-binding domain. Contains 1 pterin-binding domain.

Ontologies

Keywords
Biological process	Amino-acid biosynthesis Methionine biosynthesis
Domain	Repeat
Ligand	Cobalamin Cobalt Metal-binding S-adenosyl-L-methionine Zinc
Molecular function	Methyltransferase Transferase
Gene Ontology (GO)
Biological_process	pteridine-containing compound metabolic process Inferred from electronic annotation. Source: InterPro
Cellular_component	intracellular Inferred from electronic annotation. Source: InterPro
Molecular_function	cobalamin binding Inferred from electronic annotation. Source: UniProtKB-KW homocysteine S-methyltransferase activity Inferred from electronic annotation. Source: InterPro methionine synthase activity Inferred from electronic annotation. Source: EC zinc ion binding Inferred from electronic annotation. Source: InterPro
Complete GO annotation...

Sequence annotation (Features)

	Feature key	Position(s)	Length	Description	Graphical view	Feature identifier
Molecule processing
	Chain	1 – 1226	1226	Methionine synthase		PRO_0000204540
Regions
	Domain	7 – 327	321	Hcy-binding
	Domain	358 – 619	262	Pterin-binding
	Domain	652 – 746	95	B12-binding N-terminal
	Domain	748 – 883	136	B12-binding
	Domain	899 – 1226	328	AdoMet activation
	Region	836 – 837	2	Cobalamin-binding By similarity
	Region	1192 – 1193	2	S-adenosyl-L-methionine binding By similarity
Sites
	Metal binding	249	1	Zinc By similarity
	Metal binding	312	1	Zinc By similarity
	Metal binding	313	1	Zinc By similarity
	Metal binding	761	1	Cobalt (cobalamin axial ligand) By similarity
	Binding site	806	1	Cobalamin By similarity
	Binding site	949	1	S-adenosyl-L-methionine By similarity
	Binding site	1137	1	S-adenosyl-L-methionine; via carbonyl oxygen By similarity
	Binding site	1141	1	Cobalamin; via carbonyl oxygen By similarity

Sequences

	Sequence		Length	Mass (Da)
	Q9AJQ8 [UniParc]. Last modified June 1, 2001. Version 1. Checksum: AF210E43E119E50C	FASTA	1,226	136,266
	10 20 30 40 50 60 MAGSNIKVQI EKQLSERILL IDGGMGTMIQ GYKFEEKDYR GGRFNQWHCD LKGNNDLLVL 70 80 90 100 110 120 SQPQIIRDIH EAYLEAGADI LETNTFNATT IAMADYDMES LSEEINFEAA KLAREVADKW 130 140 150 160 170 180 TEKTPNKPRY VAGVLGPTNR TCSISPDVND PGFRNVSFDE LVEAYSESTR ALIRGGSDLI 190 200 210 220 230 240 LIETIFDTLN AKACSFAVES VFEELGITLP VMISGTITDA SGRTLSGQTT EAFYNALRHV 250 260 270 280 290 300 KPISFGLNCA LGPDELREYV SELSRISECY VSAHPNAGLP NAFGEYDLSP EDMAEHVAEW 310 320 330 340 350 360 ASSGFLNLIG GCCGTTPEHI RQMALVVEGV KPRQLPELPV ACRLSGLEPL TIEKDSLFIN 370 380 390 400 410 420 VGERTNVTGS ARFKRLIKEE LYDEALSVAQ EQVENGAQII DINMDEGMLD AEACMVRFLN 430 440 450 460 470 480 LCASEPEISK VPVMVDSSKW EVIEAGLKCI QGKGIVNSIS LKEGKEKFVH QAKLIRRYGA 490 500 510 520 530 540 AVIVMAFDEV GQADTRERKI EICTNAYNIL VDEVGFPPED IIFDPNIFAV ATGIDEHNNY 550 560 570 580 590 600 AVDFIEAVGD IKRTLPHAMI SGGVSNVSFS FRGNNYVREA IHAVFLYHCF KNGMDMGIVN 610 620 630 640 650 660 AGQLEIYDNV PEDLREAVED VVLNRRDDST ERLLDIATEY LERAVGKVED KSALEWRDWP 670 680 690 700 710 720 VEKRLEHSLV KGITEFIVED TEEARINAER PIEVIEGPLM DGMNVVGDLF GEGKMFLPQV 730 740 750 760 770 780 VKSARVMKQA VAHLEPFINA SKEVGATNGK ILLATVKGDV HDIGKNIVGV VLQCNNYEII 790 800 810 820 830 840 DLGVMVSCET ILKVAKEENV DIIGLSGLIT PSLDEMVHVA KEMERQGFDL PLLIGGATTS 850 860 870 880 890 900 KAHTAVKIEQ NYSQPVVYVN NASRAVGVCT SLLSNELKPS FVEKLDIDYE RVREQHSRKQ 910 920 930 940 950 960 PRTKPVTLEV ARANKVAIDW ASYTPPVPLK PGVHIFDNFD VSTLRNYIDW TPFFMTWSLV 970 980 990 1000 1010 1020 GKYPKILEHE EVGEEAKRLF KDANDLLDRV EKEGLLKARG MCALFPASSV GDDIEVYTDE 1030 1040 1050 1060 1070 1080 SRTTVAKVLH NLRQQTEKPK GFNYCLSDYI APKESGKNDW IGGFAVTGGI GERELADEYK 1090 1100 1110 1120 1130 1140 ANGDDYNAIM IQAVADRLAE AFAEYLHEKV RKEIWGYSPN ETLSNDDLIR EKYQGIRPAP 1150 1160 1170 1180 1190 1200 GYPACPEHTE KGALWELMNV EESIGMSLTS SYAMWPGASV SGMYFSHPDS RYFAIAQIQQ 1210 1220 DQAESYADRK GWNMLEAEKW LGPNLN

References

[1]

"Identification of the cobalamin-dependent methionine synthase gene, metH, in Vibrio fischeri ATCC 7744 by sequencing using genomic DNA as a template." Kasai S., Yamazaki T. Gene 264:281-288(2001) [PubMed] [Europe PMC] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA]. Strain: ATCC 7744 / NCIMB 1281.

Cross-references

Sequence databases
EMBL GenBank DDBJ	AB039955 Genomic DNA. Translation: BAB39355.1.
3D structure databases
ProteinModelPortal	Q9AJQ8.
SMR	Q9AJQ8. Positions 655-1225.
ModBase	Search...
Proteomic databases
PRIDE	Q9AJQ8.
Protocols and materials databases
StructuralBiologyKnowledgebase	Search...
Enzyme and pathway databases
UniPathway	UPA00051; UER00081.
Family and domain databases
Gene3D	1.10.1240.10. 1 hit. 3.10.196.10. 1 hit. 3.20.20.20. 1 hit. 3.20.20.330. 1 hit. 3.40.50.280. 1 hit.
InterPro	IPR003759. Cbl-bd_cap. IPR006158. Cobalamin-bd. IPR011005. Dihydropteroate_synth-like. IPR011822. MetH. IPR000489. Pterin-binding. IPR003726. S_MeTrfase. IPR004223. VitB12-dep_Met_synth_activ_dom. [Graphical view]
PANTHER	PTHR21091:SF9. PTHR21091:SF9. 1 hit.
Pfam	PF02310. B12-binding. 1 hit. PF02607. B12-binding_2. 1 hit. PF02965. Met_synt_B12. 1 hit. PF00809. Pterin_bind. 1 hit. PF02574. S-methyl_trans. 1 hit. [Graphical view]
PIRSF	PIRSF000381. MetH. 1 hit.
SMART	SM01018. B12-binding_2. 1 hit. [Graphical view]
SUPFAM	SSF52242. Cbl-bd. 1 hit. SSF51717. DHP_synth_like. 1 hit. SSF56507. Met_synth_B12. 1 hit. SSF47644. Met_synth_Cbl-bd. 1 hit. SSF82282. S_methyl_trans. 1 hit.
TIGRFAMs	TIGR02082. metH. 1 hit.
PROSITE	PS50974. ADOMET_ACTIVATION. 1 hit. PS51332. B12_BINDING. 1 hit. PS51337. B12_BINDING_NTER. 1 hit. PS50970. HCY. 1 hit. PS50972. PTERIN_BINDING. 1 hit. [Graphical view]
ProtoNet	Search...

Entry information

Entry name

METH_VIBFI

Accession

Primary (citable) accession number: Q9AJQ8

Entry history

Integrated into UniProtKB/Swiss-Prot:	November 22, 2005
Last sequence update:	June 1, 2001
Last modified:	April 3, 2013
This is version 62 of the entry and version 1 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation program

Prokaryotic Protein Annotation Program