ID   LUXS_STRPN              Reviewed;         160 AA.
AC   P65334; Q97SJ9;
DT   11-OCT-2004, integrated into UniProtKB/Swiss-Prot.
DT   11-OCT-2004, sequence version 1.
DT   10-JUN-2026, entry version 103.
DE   RecName: Full=S-ribosylhomocysteine lyase;
DE            EC=4.4.1.21;
DE   AltName: Full=AI-2 synthesis protein;
DE   AltName: Full=Autoinducer-2 production protein LuxS;
GN   Name=luxS; OrderedLocusNames=SP_0340;
OS   Streptococcus pneumoniae serotype 4 (strain ATCC BAA-334 / TIGR4).
OC   Bacteria; Bacillati; Bacillota; Bacilli; Lactobacillales; Streptococcaceae;
OC   Streptococcus.
OX   NCBI_TaxID=170187;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=ATCC BAA-334 / TIGR4;
RX   PubMed=11463916; DOI=10.1126/science.1061217;
RA   Tettelin H., Nelson K.E., Paulsen I.T., Eisen J.A., Read T.D.,
RA   Peterson S.N., Heidelberg J.F., DeBoy R.T., Haft D.H., Dodson R.J.,
RA   Durkin A.S., Gwinn M.L., Kolonay J.F., Nelson W.C., Peterson J.D.,
RA   Umayam L.A., White O., Salzberg S.L., Lewis M.R., Radune D.,
RA   Holtzapple E.K., Khouri H.M., Wolf A.M., Utterback T.R., Hansen C.L.,
RA   McDonald L.A., Feldblyum T.V., Angiuoli S.V., Dickinson T., Hickey E.K.,
RA   Holt I.E., Loftus B.J., Yang F., Smith H.O., Venter J.C., Dougherty B.A.,
RA   Morrison D.A., Hollingshead S.K., Fraser C.M.;
RT   "Complete genome sequence of a virulent isolate of Streptococcus
RT   pneumoniae.";
RL   Science 293:498-506(2001).
CC   -!- FUNCTION: Involved in the synthesis of autoinducer 2 (AI-2) which is
CC       secreted by bacteria and is used to communicate both the cell density
CC       and the metabolic potential of the environment. The regulation of gene
CC       expression in response to changes in cell density is called quorum
CC       sensing. Catalyzes the transformation of S-ribosylhomocysteine (RHC) to
CC       homocysteine (HC) and 4,5-dihydroxy-2,3-pentadione (DPD) (By
CC       similarity). {ECO:0000250}.
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=S-(5-deoxy-D-ribos-5-yl)-L-homocysteine = (S)-4,5-
CC         dihydroxypentane-2,3-dione + L-homocysteine; Xref=Rhea:RHEA:17753,
CC         ChEBI:CHEBI:29484, ChEBI:CHEBI:58195, ChEBI:CHEBI:58199; EC=4.4.1.21;
CC   -!- COFACTOR:
CC       Name=Fe cation; Xref=ChEBI:CHEBI:24875; Evidence={ECO:0000250};
CC       Note=Binds 1 Fe cation per subunit. {ECO:0000250};
CC   -!- SUBUNIT: Homodimer. {ECO:0000250}.
CC   -!- SIMILARITY: Belongs to the LuxS family. {ECO:0000305}.
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DR   EMBL; AE005672; AAK74514.1; -; Genomic_DNA.
DR   PIR; A95040; A95040.
DR   RefSeq; WP_000032550.1; NC_003028.3.
DR   AlphaFoldDB; P65334; -.
DR   SMR; P65334; -.
DR   EnsemblBacteria; AAK74514; AAK74514; SP_0340.
DR   GeneID; 45652192; -.
DR   KEGG; spn:SP_0340; -.
DR   eggNOG; COG1854; Bacteria.
DR   PhylomeDB; P65334; -.
DR   BioCyc; SPNE170187:G1FZB-349-MONOMER; -.
DR   Proteomes; UP000000585; Chromosome.
DR   GO; GO:0005506; F:iron ion binding; IEA:InterPro.
DR   GO; GO:0043768; F:S-ribosylhomocysteine lyase activity; IEA:UniProtKB-UniRule.
DR   GO; GO:0009372; P:quorum sensing; IEA:UniProtKB-UniRule.
DR   Gene3D; 3.30.1360.80; S-ribosylhomocysteinase (LuxS); 1.
DR   HAMAP; MF_00091; LuxS; 1.
DR   InterPro; IPR037005; LuxS_sf.
DR   InterPro; IPR011249; Metalloenz_LuxS/M16.
DR   InterPro; IPR003815; S-ribosylhomocysteinase.
DR   NCBIfam; NF002607; PRK02260.2-5; 1.
DR   NCBIfam; NF002608; PRK02260.3-1; 1.
DR   PANTHER; PTHR35799; S-RIBOSYLHOMOCYSTEINE LYASE; 1.
DR   PANTHER; PTHR35799:SF1; S-RIBOSYLHOMOCYSTEINE LYASE; 1.
DR   Pfam; PF02664; LuxS; 1.
DR   PIRSF; PIRSF006160; AI2; 1.
DR   PRINTS; PR01487; LUXSPROTEIN.
DR   SUPFAM; SSF63411; LuxS/MPP-like metallohydrolase; 1.
PE   3: Inferred from homology;
KW   Autoinducer synthesis; Iron; Lyase; Metal-binding; Quorum sensing;
KW   Reference proteome.
FT   CHAIN           1..160
FT                   /note="S-ribosylhomocysteine lyase"
FT                   /id="PRO_0000172265"
FT   BINDING         57
FT                   /ligand="Fe cation"
FT                   /ligand_id="ChEBI:CHEBI:24875"
FT                   /evidence="ECO:0000250"
FT   BINDING         61
FT                   /ligand="Fe cation"
FT                   /ligand_id="ChEBI:CHEBI:24875"
FT                   /evidence="ECO:0000250"
FT   BINDING         127
FT                   /ligand="Fe cation"
FT                   /ligand_id="ChEBI:CHEBI:24875"
FT                   /evidence="ECO:0000250"
SQ   SEQUENCE   160 AA;  17923 MW;  4992A6E764A4D324 CRC64;
     MSKEVIVESF ELDHTIVKAP YVRLIGEETG PKGDIISNYD IRLVQPNEDS IPTAGLHTIE
     HLLAKLIRTR IDGMIDCSPF GCRTGFHMIM WGRHTSAKIA AVIKDSLKEI AETTTWEDVP
     GTTIESCGNY KDHSLFSAKE WAKLILEQGI SDDAFERHVI
//