ID   SP2SB_BACSU             Reviewed;          56 AA.
AC   O34800;
DT   03-APR-2002, integrated into UniProtKB/Swiss-Prot.
DT   01-JAN-1998, sequence version 1.
DT   03-AUG-2022, entry version 105.
DE   RecName: Full=Stage II sporulation protein SB;
DE   AltName: Full=Antidote protein SpoIISB;
DE   AltName: Full=Antitoxin SpoIISB;
GN   Name=spoIISB; OrderedLocusNames=BSU12820;
OS   Bacillus subtilis (strain 168).
OC   Bacteria; Firmicutes; Bacilli; Bacillales; Bacillaceae; Bacillus.
OX   NCBI_TaxID=224308;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RC   STRAIN=168;
RA   Devine K.M.;
RT   "Sequence of the Bacillus subtilis genome between xlyA and ykoR.";
RL   Submitted (NOV-1997) to the EMBL/GenBank/DDBJ databases.
RN   [2]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=168;
RX   PubMed=9384377; DOI=10.1038/36786;
RA   Kunst F., Ogasawara N., Moszer I., Albertini A.M., Alloni G., Azevedo V.,
RA   Bertero M.G., Bessieres P., Bolotin A., Borchert S., Borriss R.,
RA   Boursier L., Brans A., Braun M., Brignell S.C., Bron S., Brouillet S.,
RA   Bruschi C.V., Caldwell B., Capuano V., Carter N.M., Choi S.-K.,
RA   Codani J.-J., Connerton I.F., Cummings N.J., Daniel R.A., Denizot F.,
RA   Devine K.M., Duesterhoeft A., Ehrlich S.D., Emmerson P.T., Entian K.-D.,
RA   Errington J., Fabret C., Ferrari E., Foulger D., Fritz C., Fujita M.,
RA   Fujita Y., Fuma S., Galizzi A., Galleron N., Ghim S.-Y., Glaser P.,
RA   Goffeau A., Golightly E.J., Grandi G., Guiseppi G., Guy B.J., Haga K.,
RA   Haiech J., Harwood C.R., Henaut A., Hilbert H., Holsappel S., Hosono S.,
RA   Hullo M.-F., Itaya M., Jones L.-M., Joris B., Karamata D., Kasahara Y.,
RA   Klaerr-Blanchard M., Klein C., Kobayashi Y., Koetter P., Koningstein G.,
RA   Krogh S., Kumano M., Kurita K., Lapidus A., Lardinois S., Lauber J.,
RA   Lazarevic V., Lee S.-M., Levine A., Liu H., Masuda S., Mauel C.,
RA   Medigue C., Medina N., Mellado R.P., Mizuno M., Moestl D., Nakai S.,
RA   Noback M., Noone D., O'Reilly M., Ogawa K., Ogiwara A., Oudega B.,
RA   Park S.-H., Parro V., Pohl T.M., Portetelle D., Porwollik S.,
RA   Prescott A.M., Presecan E., Pujic P., Purnelle B., Rapoport G., Rey M.,
RA   Reynolds S., Rieger M., Rivolta C., Rocha E., Roche B., Rose M., Sadaie Y.,
RA   Sato T., Scanlan E., Schleich S., Schroeter R., Scoffone F., Sekiguchi J.,
RA   Sekowska A., Seror S.J., Serror P., Shin B.-S., Soldo B., Sorokin A.,
RA   Tacconi E., Takagi T., Takahashi H., Takemaru K., Takeuchi M.,
RA   Tamakoshi A., Tanaka T., Terpstra P., Tognoni A., Tosato V., Uchiyama S.,
RA   Vandenbol M., Vannier F., Vassarotti A., Viari A., Wambutt R., Wedler E.,
RA   Wedler H., Weitzenegger T., Winters P., Wipat A., Yamamoto H., Yamane K.,
RA   Yasumoto K., Yata K., Yoshida K., Yoshikawa H.-F., Zumstein E.,
RA   Yoshikawa H., Danchin A.;
RT   "The complete genome sequence of the Gram-positive bacterium Bacillus
RT   subtilis.";
RL   Nature 390:249-256(1997).
RN   [3]
RP   FUNCTION AS AN ANTITOXIN, INDUCTION, AND DISRUPTION PHENOTYPE.
RC   STRAIN=168 / JH642;
RX   PubMed=11371520; DOI=10.1128/jb.183.12.3574-3581.2001;
RA   Adler E., Barak I., Stragier P.;
RT   "Bacillus subtilis locus encoding a killer protein and its antidote.";
RL   J. Bacteriol. 183:3574-3581(2001).
RN   [4]
RP   EXPRESSION IN E.COLI.
RC   STRAIN=168 / JH642;
RX   PubMed=18096016; DOI=10.1111/j.1574-6968.2007.00984.x;
RA   Florek P., Muchova K., Pavelcikova P., Barak I.;
RT   "Expression of functional Bacillus SpoIISAB toxin-antitoxin modules in
RT   Escherichia coli.";
RL   FEMS Microbiol. Lett. 278:177-184(2008).
RN   [5]
RP   X-RAY CRYSTALLOGRAPHY (2.5 ANGSTROMS), INTERACTION WITH SPOIISA, AND
RP   MUTAGENESIS OF 1-MET--ARG-12 AND 53-ARG--ALA-56.
RC   STRAIN=168 / PY79;
RX   PubMed=21147767; DOI=10.1074/jbc.m110.172429;
RA   Florek P., Levdikov V.M., Blagova E., Lebedev A.A., Skrabana R.,
RA   Resetarova S., Pavelcikova P., Barak I., Wilkinson A.J.;
RT   "The structure and interactions of SpoIISA and SpoIISB, a toxin-antitoxin
RT   system in Bacillus subtilis.";
RL   J. Biol. Chem. 286:6808-6819(2011).
CC   -!- FUNCTION: Antitoxin component of a type II toxin-antitoxin (TA) system.
CC       Antitoxin that binds cognate toxin SpoIISA and neutralizes its toxic
CC       activity; unlike most antitoxins it does not seem to be highly labile
CC       upon expression in E.coli. {ECO:0000269|PubMed:11371520}.
CC   -!- SUBUNIT: The isolated protein is unfolded; X-ray data suggests the
CC       inactive complex forms a heterotetramer of SpoIISA(2)-SpoIISB(2), which
CC       inactivates the toxic activity of SpoIISA.
CC   -!- INTERACTION:
CC       O34800; O34853: spoIISA; NbExp=3; IntAct=EBI-4406141, EBI-4406150;
CC   -!- INDUCTION: Expressed during exponential growth and sporulation. A
CC       member of the spoIISA-spoIISB operon, it also has its own promoter.
CC       {ECO:0000269|PubMed:11371520}.
CC   -!- DISRUPTION PHENOTYPE: Decreases sporulation efficiency by 4 orders of
CC       magnitude. A double spoIISA-spoIISB disruption sporulates normally,
CC       suggesting its only role is to neutralize SpoIISA.
CC       {ECO:0000269|PubMed:11371520}.
CC   -!- SIMILARITY: Belongs to the SpoIISB antitoxin family. {ECO:0000305}.
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DR   EMBL; AJ002571; CAA05562.1; -; Genomic_DNA.
DR   EMBL; AL009126; CAB13139.1; -; Genomic_DNA.
DR   PIR; E69713; E69713.
DR   RefSeq; NP_389165.1; NC_000964.3.
DR   RefSeq; WP_003232646.1; NZ_JNCM01000035.1.
DR   PDB; 3O6Q; X-ray; 2.50 A; B/D=1-56.
DR   PDBsum; 3O6Q; -.
DR   AlphaFoldDB; O34800; -.
DR   SMR; O34800; -.
DR   IntAct; O34800; 1.
DR   STRING; 224308.BSU12820; -.
DR   PaxDb; O34800; -.
DR   PRIDE; O34800; -.
DR   EnsemblBacteria; CAB13139; CAB13139; BSU_12820.
DR   GeneID; 938005; -.
DR   KEGG; bsu:BSU12820; -.
DR   PATRIC; fig|224308.179.peg.1391; -.
DR   eggNOG; ENOG5030D7K; Bacteria.
DR   OMA; RAAKPFK; -.
DR   BioCyc; BSUB:BSU12820-MON; -.
DR   Proteomes; UP000001570; Chromosome.
DR   GO; GO:0030435; P:sporulation resulting in formation of a cellular spore; IEA:UniProtKB-KW.
DR   DisProt; DP01146; -.
DR   InterPro; IPR025897; Antitoxin_SpoIISB.
DR   Pfam; PF14185; SpoIISB_antitox; 1.
PE   1: Evidence at protein level;
KW   3D-structure; Reference proteome; Sporulation; Toxin-antitoxin system.
FT   CHAIN           1..56
FT                   /note="Stage II sporulation protein SB"
FT                   /id="PRO_0000072063"
FT   MUTAGEN         1..12
FT                   /note="MERAFQNRCEPR->MA: No loss of antitoxin activity."
FT                   /evidence="ECO:0000269|PubMed:21147767"
FT   MUTAGEN         53..56
FT                   /note="Missing: Significant loss of antitoxin activity."
FT                   /evidence="ECO:0000269|PubMed:21147767"
FT   STRAND          17..21
FT                   /evidence="ECO:0007829|PDB:3O6Q"
FT   STRAND          25..28
FT                   /evidence="ECO:0007829|PDB:3O6Q"
FT   HELIX           35..48
FT                   /evidence="ECO:0007829|PDB:3O6Q"
SQ   SEQUENCE   56 AA;  6655 MW;  E8469AB7D4EE2B7F CRC64;
     MERAFQNRCE PRAAKPFKIL KKRSTTSVAS YQVSPHTARI FKENERLIDE YKRKKA