ID   SSRP_BUCAT              Reviewed;         162 AA.
AC   B8D7F1;
DT   28-JUL-2009, integrated into UniProtKB/Swiss-Prot.
DT   03-MAR-2009, sequence version 1.
DT   03-AUG-2022, entry version 66.
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=BUAPTUC7_251;
OS   Buchnera aphidicola subsp. Acyrthosiphon pisum (strain Tuc7).
OC   Bacteria; Proteobacteria; Gammaproteobacteria; Enterobacterales;
OC   Erwiniaceae; Buchnera.
OX   NCBI_TaxID=561501;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=Tuc7;
RX   PubMed=19150844; DOI=10.1126/science.1167140;
RA   Moran N.A., McLaughlin H.J., Sorek R.;
RT   "The dynamics and time scale of ongoing genomic erosion in symbiotic
RT   bacteria.";
RL   Science 323:379-382(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; CP001158; ACL30066.1; -; Genomic_DNA.
DR   RefSeq; WP_009874208.1; NC_011834.1.
DR   AlphaFoldDB; B8D7F1; -.
DR   SMR; B8D7F1; -.
DR   KEGG; bau:BUAPTUC7_251; -.
DR   HOGENOM; CLU_108953_3_0_6; -.
DR   OMA; WTNHSAR; -.
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..162
FT                   /note="SsrA-binding protein"
FT                   /id="PRO_1000197611"
SQ   SEQUENCE   162 AA;  19336 MW;  E418AA8E2B030E29 CRC64;
     MLQKKKYQKK SSKIIINKKA YYNYFIEKVF QSGLVLEGWE IKSIRSGKVN ISESYIINDR
     NEMYLCNCLI EPLQMSSNRF SCDPTRKKKL LLHKNEIDFL SLKKKNTGYT MVSLSLFWKK
     SWCKLEFGLA KGKTAQDKRI NLKKREWEQE KLKILKKTKE TY