ID   SSRP_CALS8              Reviewed;         158 AA.
AC   A4XIH3;
DT   29-APR-2008, integrated into UniProtKB/Swiss-Prot.
DT   29-MAY-2007, sequence version 1.
DT   25-MAY-2022, entry version 80.
DE   RecName: Full=SsrA-binding protein {ECO:0000255|HAMAP-Rule:MF_00023};
DE   AltName: Full=Small protein B {ECO:0000255|HAMAP-Rule:MF_00023};
GN   Name=smpB {ECO:0000255|HAMAP-Rule:MF_00023}; OrderedLocusNames=Csac_1095;
OS   Caldicellulosiruptor saccharolyticus (strain ATCC 43494 / DSM 8903 / Tp8T
OS   6331).
OC   Bacteria; Firmicutes; Clostridia; Thermoanaerobacterales;
OC   Thermoanaerobacterales Family III. Incertae Sedis; Caldicellulosiruptor.
OX   NCBI_TaxID=351627;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=ATCC 43494 / DSM 8903 / Tp8T 6331;
RA   Copeland A., Lucas S., Lapidus A., Barry K., Detter J.C.,
RA   Glavina del Rio T., Hammon N., Israni S., Dalin E., Tice H., Pitluck S.,
RA   Kiss H., Brettin T., Bruce D., Han C., Schmutz J., Larimer F., Land M.,
RA   Hauser L., Kyrpides N., Lykidis A., van de Werken H.J.G., Verhaart M.R.A.,
RA   VanFossen A.L., Lewis D.L., Nichols J.D., Goorissen H.P., van Niel E.W.J.,
RA   Stams F.J.M., Willquist K.U., Ward D.E., van der Oost J., Kelly R.M.,
RA   Kengen S.M.W., Richardson P.;
RT   "Genome sequence of the thermophilic hydrogen-producing bacterium
RT   Caldicellulosiruptor saccharolyticus DSM 8903.";
RL   Submitted (APR-2007) to the EMBL/GenBank/DDBJ databases.
CC   -!- FUNCTION: Required for rescue of stalled ribosomes mediated by trans-
CC       translation. Binds to transfer-messenger RNA (tmRNA), required for
CC       stable association of tmRNA with ribosomes. tmRNA and SmpB together
CC       mimic tRNA shape, replacing the anticodon stem-loop with SmpB. tmRNA is
CC       encoded by the ssrA gene; the 2 termini fold to resemble tRNA(Ala) and
CC       it encodes a 'tag peptide', a short internal open reading frame. During
CC       trans-translation Ala-aminoacylated tmRNA acts like a tRNA, entering
CC       the A-site of stalled ribosomes, displacing the stalled mRNA. The
CC       ribosome then switches to translate the ORF on the tmRNA; the nascent
CC       peptide is terminated with the 'tag peptide' encoded by the tmRNA and
CC       targeted for degradation. The ribosome is freed to recommence
CC       translation, which seems to be the essential function of trans-
CC       translation. {ECO:0000255|HAMAP-Rule:MF_00023}.
CC   -!- SUBCELLULAR LOCATION: Cytoplasm {ECO:0000255|HAMAP-Rule:MF_00023}.
CC       Note=The tmRNA-SmpB complex associates with stalled 70S ribosomes.
CC       {ECO:0000255|HAMAP-Rule:MF_00023}.
CC   -!- SIMILARITY: Belongs to the SmpB family. {ECO:0000255|HAMAP-
CC       Rule:MF_00023}.
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DR   EMBL; CP000679; ABP66708.1; -; Genomic_DNA.
DR   RefSeq; WP_011916654.1; NC_009437.1.
DR   AlphaFoldDB; A4XIH3; -.
DR   SMR; A4XIH3; -.
DR   STRING; 351627.Csac_1095; -.
DR   EnsemblBacteria; ABP66708; ABP66708; Csac_1095.
DR   KEGG; csc:Csac_1095; -.
DR   eggNOG; COG0691; Bacteria.
DR   HOGENOM; CLU_108953_0_0_9; -.
DR   OMA; WTNHSAR; -.
DR   OrthoDB; 1720952at2; -.
DR   Proteomes; UP000000256; Chromosome.
DR   GO; GO:0005737; C:cytoplasm; IEA:UniProtKB-SubCell.
DR   GO; GO:0003723; F:RNA binding; IEA:UniProtKB-UniRule.
DR   GO; GO:0070929; P:trans-translation; IEA:UniProtKB-UniRule.
DR   CDD; cd09294; SmpB; 1.
DR   Gene3D; 2.40.280.10; -; 1.
DR   HAMAP; MF_00023; SmpB; 1.
DR   InterPro; IPR023620; SmpB.
DR   InterPro; IPR000037; SsrA-bd_prot.
DR   InterPro; IPR020081; SsrA-bd_prot_CS.
DR   PANTHER; PTHR30308; PTHR30308; 1.
DR   Pfam; PF01668; SmpB; 1.
DR   SUPFAM; SSF74982; SSF74982; 1.
DR   TIGRFAMs; TIGR00086; smpB; 1.
DR   PROSITE; PS01317; SSRP; 1.
PE   3: Inferred from homology;
KW   Cytoplasm; RNA-binding.
FT   CHAIN           1..158
FT                   /note="SsrA-binding protein"
FT                   /id="PRO_0000331026"
SQ   SEQUENCE   158 AA;  18453 MW;  1DA946D676760111 CRC64;
     MAEKNKQDDI KVIATNRKAY HDYFIEETIE AGIELKGTEV KSVRLGHVNL KDSFARVENG
     EVFLYNMHIS PYEKGNIFNV DPMRDRKLLL HKSEINRLAG YVQQKGYTLI PLKIYLKRGK
     IKVELAVAKG KKLFDKREAI AKRDAELEIR KKMKEYLR