ID   SSRP_LACH4              Reviewed;         152 AA.
AC   A8YTT9;
DT   29-APR-2008, integrated into UniProtKB/Swiss-Prot.
DT   15-JAN-2008, sequence version 1.
DT   25-MAY-2022, entry version 79.
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=lhv_0473;
OS   Lactobacillus helveticus (strain DPC 4571).
OC   Bacteria; Firmicutes; Bacilli; Lactobacillales; Lactobacillaceae;
OC   Lactobacillus.
OX   NCBI_TaxID=405566;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=DPC 4571;
RX   PubMed=17993529; DOI=10.1128/jb.01295-07;
RA   Callanan M., Kaleta P., O'Callaghan J., O'Sullivan O., Jordan K.,
RA   McAuliffe O., Sangrador-Vegas A., Slattery L., Fitzgerald G.F.,
RA   Beresford T., Ross R.P.;
RT   "Genome sequence of Lactobacillus helveticus: an organism distinguished by
RT   selective gene loss and IS element expansion.";
RL   J. Bacteriol. 190:727-735(2008).
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; CP000517; ABX26680.1; -; Genomic_DNA.
DR   RefSeq; WP_003627921.1; NC_010080.1.
DR   AlphaFoldDB; A8YTT9; -.
DR   SMR; A8YTT9; -.
DR   STRING; 405566.lhv_0473; -.
DR   EnsemblBacteria; ABX26680; ABX26680; lhv_0473.
DR   GeneID; 66452795; -.
DR   KEGG; lhe:lhv_0473; -.
DR   eggNOG; COG0691; Bacteria.
DR   HOGENOM; CLU_108953_0_0_9; -.
DR   OMA; WTNHSAR; -.
DR   Proteomes; UP000000790; 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..152
FT                   /note="SsrA-binding protein"
FT                   /id="PRO_0000331057"
SQ   SEQUENCE   152 AA;  17718 MW;  1A6F6E6516993A0C CRC64;
     MKKEKDDNLI AQNKKARHDY FIKETVEAGI ALTGTEIKSV RARRINLRDG YVQIYGGSAY
     LENVHISEYK QGNRYNHDPL RSRRLLLHKK EIARLAKAQS ERGIAIIPLK VYLKHGFAKV
     LIGVGQGKKE YDKRQTIKER DQKREIRRKY GI