ID   SSRP_SOLUE              Reviewed;         156 AA.
AC   Q02A69;
DT   29-APR-2008, integrated into UniProtKB/Swiss-Prot.
DT   14-NOV-2006, sequence version 1.
DT   28-JAN-2026, entry version 97.
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};
GN   OrderedLocusNames=Acid_1059;
OS   Solibacter usitatus (strain Ellin6076).
OC   Bacteria; Pseudomonadati; Acidobacteriota; Terriglobia; Bryobacterales;
OC   Solibacteraceae; Candidatus Solibacter.
OX   NCBI_TaxID=234267;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=Ellin6076;
RX   PubMed=19201974; DOI=10.1128/aem.02294-08;
RA   Ward N.L., Challacombe J.F., Janssen P.H., Henrissat B., Coutinho P.M.,
RA   Wu M., Xie G., Haft D.H., Sait M., Badger J., Barabote R.D., Bradley B.,
RA   Brettin T.S., Brinkac L.M., Bruce D., Creasy T., Daugherty S.C.,
RA   Davidsen T.M., DeBoy R.T., Detter J.C., Dodson R.J., Durkin A.S.,
RA   Ganapathy A., Gwinn-Giglio M., Han C.S., Khouri H., Kiss H., Kothari S.P.,
RA   Madupu R., Nelson K.E., Nelson W.C., Paulsen I., Penn K., Ren Q.,
RA   Rosovitz M.J., Selengut J.D., Shrivastava S., Sullivan S.A., Tapia R.,
RA   Thompson L.S., Watkins K.L., Yang Q., Yu C., Zafar N., Zhou L., Kuske C.R.;
RT   "Three genomes from the phylum Acidobacteria provide insight into the
RT   lifestyles of these microorganisms in soils.";
RL   Appl. Environ. Microbiol. 75:2046-2056(2009).
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; CP000473; ABJ82057.1; -; Genomic_DNA.
DR   AlphaFoldDB; Q02A69; -.
DR   SMR; Q02A69; -.
DR   FunCoup; Q02A69; 496.
DR   STRING; 234267.Acid_1059; -.
DR   KEGG; sus:Acid_1059; -.
DR   eggNOG; COG0691; Bacteria.
DR   HOGENOM; CLU_108953_0_0_0; -.
DR   InParanoid; Q02A69; -.
DR   OrthoDB; 9805462at2; -.
DR   GO; GO:0005829; C:cytosol; IEA:TreeGrafter.
DR   GO; GO:0003723; F:RNA binding; IEA:UniProtKB-UniRule.
DR   GO; GO:0070929; P:trans-translation; IEA:UniProtKB-UniRule.
DR   GO; GO:0070930; P:trans-translation-dependent protein tagging; IEA:TreeGrafter.
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   NCBIfam; NF003843; PRK05422.1; 1.
DR   NCBIfam; TIGR00086; smpB; 1.
DR   PANTHER; PTHR30308:SF2; SSRA-BINDING PROTEIN; 1.
DR   PANTHER; PTHR30308; TMRNA-BINDING COMPONENT OF TRANS-TRANSLATION TAGGING COMPLEX; 1.
DR   Pfam; PF01668; SmpB; 1.
DR   SUPFAM; SSF74982; Small protein B (SmpB); 1.
DR   PROSITE; PS01317; SSRP; 1.
PE   3: Inferred from homology;
KW   Cytoplasm; RNA-binding.
FT   CHAIN           1..156
FT                   /note="SsrA-binding protein"
FT                   /id="PRO_0000331097"
FT   REGION          135..156
FT                   /note="Disordered"
FT                   /evidence="ECO:0000256|SAM:MobiDB-lite"
SQ   SEQUENCE   156 AA;  17870 MW;  B36AC1AA38DABA49 CRC64;
     MADKKDFAFK ILSDNRQAGH NYFLSERFEC GMVLTGTEVK AAKDAKIQLK DAYASVLGDE
     AWLLNAHISQ YSHGNRENHL PVRNRKLLLH RREIDKLQEI TREKGLALIP TKIYMKNGKI
     KCEIAVAKGK KLYDKRAADK ARTADDEARA EMRRRA
//