SIHH_METMP
ID SIHH_METMP Reviewed; 415 AA.
AC Q6LYR8;
DT 01-FEB-2005, integrated into UniProtKB/Swiss-Prot.
DT 05-JUL-2004, sequence version 1.
DT 03-AUG-2022, entry version 106.
DE RecName: Full=S-inosyl-L-homocysteine hydrolase {ECO:0000255|HAMAP-Rule:MF_00563};
DE Short=SIHH {ECO:0000255|HAMAP-Rule:MF_00563};
DE EC=3.13.1.9 {ECO:0000255|HAMAP-Rule:MF_00563};
GN Name=ahcY {ECO:0000312|EMBL:CAF30476.1}; OrderedLocusNames=MMP0920;
OS Methanococcus maripaludis (strain S2 / LL).
OC Archaea; Euryarchaeota; Methanomada group; Methanococci; Methanococcales;
OC Methanococcaceae; Methanococcus.
OX NCBI_TaxID=267377;
RN [1]
RP NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC STRAIN=S2 / LL;
RX PubMed=15466049; DOI=10.1128/jb.186.20.6956-6969.2004;
RA Hendrickson E.L., Kaul R., Zhou Y., Bovee D., Chapman P., Chung J.,
RA Conway de Macario E., Dodsworth J.A., Gillett W., Graham D.E., Hackett M.,
RA Haydock A.K., Kang A., Land M.L., Levy R., Lie T.J., Major T.A.,
RA Moore B.C., Porat I., Palmeiri A., Rouse G., Saenphimmachak C., Soell D.,
RA Van Dien S., Wang T., Whitman W.B., Xia Q., Zhang Y., Larimer F.W.,
RA Olson M.V., Leigh J.A.;
RT "Complete genome sequence of the genetically tractable hydrogenotrophic
RT methanogen Methanococcus maripaludis.";
RL J. Bacteriol. 186:6956-6969(2004).
CC -!- FUNCTION: Catalyzes the hydrolysis of S-inosyl-L-homocysteine (SIH) to
CC L-homocysteine (Hcy) and inosine. Likely functions in a S-adenosyl-L-
CC methionine (SAM) recycling pathway from S-adenosyl-L-homocysteine (SAH)
CC produced from SAM-dependent methylation reactions. Can also catalyze
CC the reverse reaction in vitro, i.e. the synthesis of SIH from Hcy and
CC inosine. {ECO:0000255|HAMAP-Rule:MF_00563}.
CC -!- CATALYTIC ACTIVITY:
CC Reaction=H2O + S-inosyl-L-homocysteine = inosine + L-homocysteine;
CC Xref=Rhea:RHEA:59828, ChEBI:CHEBI:15377, ChEBI:CHEBI:17596,
CC ChEBI:CHEBI:57985, ChEBI:CHEBI:58199; EC=3.13.1.9;
CC Evidence={ECO:0000255|HAMAP-Rule:MF_00563};
CC PhysiologicalDirection=left-to-right; Xref=Rhea:RHEA:59829;
CC Evidence={ECO:0000255|HAMAP-Rule:MF_00563};
CC -!- COFACTOR:
CC Name=NAD(+); Xref=ChEBI:CHEBI:57540;
CC Evidence={ECO:0000255|HAMAP-Rule:MF_00563};
CC Note=Binds 1 NAD(+) per subunit. {ECO:0000255|HAMAP-Rule:MF_00563};
CC -!- PATHWAY: Amino-acid biosynthesis; S-adenosyl-L-methionine biosynthesis.
CC {ECO:0000255|HAMAP-Rule:MF_00563}.
CC -!- SUBCELLULAR LOCATION: Cytoplasm {ECO:0000255|HAMAP-Rule:MF_00563}.
CC -!- MISCELLANEOUS: SAH is a product of SAM methyltransferases and is known
CC to be a feedback inhibitor of these enzymes. As a result of this
CC inhibition, organisms have evolved efficient enzymes to metabolize SAH
CC via different pathways. The pathway found in methanogens differs from
CC the canonical pathway, it uses the deamination of S-adenosyl-L-
CC homocysteine to form S-inosyl-L-homocysteine for the regeneration of
CC SAM from S-adenosyl-L-homocysteine. {ECO:0000255|HAMAP-Rule:MF_00563}.
CC -!- SIMILARITY: Belongs to the adenosylhomocysteinase family.
CC {ECO:0000255|HAMAP-Rule:MF_00563}.
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DR EMBL; BX950229; CAF30476.1; -; Genomic_DNA.
DR RefSeq; WP_011170864.1; NC_005791.1.
DR AlphaFoldDB; Q6LYR8; -.
DR SMR; Q6LYR8; -.
DR STRING; 267377.MMP0920; -.
DR EnsemblBacteria; CAF30476; CAF30476; MMP0920.
DR GeneID; 2761229; -.
DR KEGG; mmp:MMP0920; -.
DR PATRIC; fig|267377.15.peg.948; -.
DR eggNOG; arCOG04137; Archaea.
DR HOGENOM; CLU_025194_2_1_2; -.
DR OMA; NKYGCRE; -.
DR OrthoDB; 17629at2157; -.
DR BioCyc; MMAR267377:MMP_RS04775-MON; -.
DR UniPathway; UPA00315; -.
DR Proteomes; UP000000590; Chromosome.
DR GO; GO:0005737; C:cytoplasm; IEA:UniProtKB-SubCell.
DR GO; GO:0004013; F:adenosylhomocysteinase activity; IEA:InterPro.
DR GO; GO:0006730; P:one-carbon metabolic process; IEA:UniProtKB-UniRule.
DR GO; GO:0006556; P:S-adenosylmethionine biosynthetic process; IEA:UniProtKB-UniPathway.
DR CDD; cd00401; SAHH; 1.
DR Gene3D; 3.40.50.1480; -; 1.
DR HAMAP; MF_00563; AdoHcyase; 1.
DR InterPro; IPR042172; Adenosylhomocyst_ase-like_sf.
DR InterPro; IPR000043; Adenosylhomocysteinase-like.
DR InterPro; IPR015878; Ado_hCys_hydrolase_NAD-bd.
DR InterPro; IPR036291; NAD(P)-bd_dom_sf.
DR InterPro; IPR020082; S-Ado-L-homoCys_hydrolase_CS.
DR PANTHER; PTHR23420; PTHR23420; 1.
DR Pfam; PF05221; AdoHcyase; 2.
DR Pfam; PF00670; AdoHcyase_NAD; 1.
DR PIRSF; PIRSF001109; Ad_hcy_hydrolase; 1.
DR SMART; SM00996; AdoHcyase; 1.
DR SMART; SM00997; AdoHcyase_NAD; 1.
DR SUPFAM; SSF51735; SSF51735; 1.
DR TIGRFAMs; TIGR00936; ahcY; 1.
DR PROSITE; PS00738; ADOHCYASE_1; 1.
DR PROSITE; PS00739; ADOHCYASE_2; 1.
PE 3: Inferred from homology;
KW Cytoplasm; Hydrolase; NAD; One-carbon metabolism; Reference proteome.
FT CHAIN 1..415
FT /note="S-inosyl-L-homocysteine hydrolase"
FT /id="PRO_0000117007"
FT BINDING 123
FT /ligand="substrate"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00563"
FT BINDING 148
FT /ligand="substrate"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00563"
FT BINDING 149..151
FT /ligand="NAD(+)"
FT /ligand_id="ChEBI:CHEBI:57540"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00563"
FT BINDING 178
FT /ligand="substrate"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00563"
FT BINDING 182
FT /ligand="substrate"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00563"
FT BINDING 183
FT /ligand="NAD(+)"
FT /ligand_id="ChEBI:CHEBI:57540"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00563"
FT BINDING 212..217
FT /ligand="NAD(+)"
FT /ligand_id="ChEBI:CHEBI:57540"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00563"
FT BINDING 235
FT /ligand="NAD(+)"
FT /ligand_id="ChEBI:CHEBI:57540"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00563"
FT BINDING 291..293
FT /ligand="NAD(+)"
FT /ligand_id="ChEBI:CHEBI:57540"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00563"
FT BINDING 337
FT /ligand="NAD(+)"
FT /ligand_id="ChEBI:CHEBI:57540"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00563"
SQ SEQUENCE 415 AA; 45834 MW; 8830AF3625379A26 CRC64;
MSNVKDMSLA PSGHLKMEWA KRHMPVLCRI AEEFKNDKPF EGLTIGMALH LEAKTAILAE
TLLEGGAKIV ITGCNPLSTQ DDVAAACVEK GMEVYAWRGE TNEEYYENLN KVLDSNPDII
IDDGADLIFL IHTERTELIG KIMGGCEETT TGIIRLKSMA EEGALKFPVV NVNDAYTKHL
FDNRYGTGQS AMDGIIRTTN LLIAGKNVVV GGYGWCGRGV ASRAAGHGAN VIITEVNPIR
ALEAKMDGFT VLKMEEAAKI GDIFVTTTGC KDILRMEHFL LMKDGAVLSN AGHFDNEINK
NDLKELSKSV KEARFNIEEY DLGNKKIYLL GEGRLVNLAC ADGHPCEVMD MSFANQALSA
KFIKENKGKL ENEVYEIPYE QDFKIALLKL HSMGADIDEL SPEQRKYLSD WKEGT
