ID   SSRP_ECOBW              Reviewed;         160 AA.
AC   C4ZYN7;
DT   22-SEP-2009, integrated into UniProtKB/Swiss-Prot.
DT   28-JUL-2009, sequence version 1.
DT   25-MAY-2022, entry version 69.
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=BWG_2378;
OS   Escherichia coli (strain K12 / MC4100 / BW2952).
OC   Bacteria; Proteobacteria; Gammaproteobacteria; Enterobacterales;
OC   Enterobacteriaceae; Escherichia.
OX   NCBI_TaxID=595496;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=K12 / MC4100 / BW2952;
RX   PubMed=19376874; DOI=10.1128/jb.00118-09;
RA   Ferenci T., Zhou Z., Betteridge T., Ren Y., Liu Y., Feng L., Reeves P.R.,
RA   Wang L.;
RT   "Genomic sequencing reveals regulatory mutations and recombinational events
RT   in the widely used MC4100 lineage of Escherichia coli K-12.";
RL   J. Bacteriol. 191:4025-4029(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; CP001396; ACR65693.1; -; Genomic_DNA.
DR   RefSeq; WP_000162574.1; NC_012759.1.
DR   AlphaFoldDB; C4ZYN7; -.
DR   SMR; C4ZYN7; -.
DR   GeneID; 67414063; -.
DR   KEGG; ebw:BWG_2378; -.
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..160
FT                   /note="SsrA-binding protein"
FT                   /id="PRO_1000201932"
SQ   SEQUENCE   160 AA;  18269 MW;  F7E45A16540EA300 CRC64;
     MTKKKAHKPG SATIALNKRA RHEYFIEEEF EAGLALQGWE VKSLRAGKAN ISDSYVLLRD
     GEAFLFGANI TPMAVASTHV VCDPTRTRKL LLNQRELDSL YGRVNREGYT VVALSLYWKN
     AWCKVKIGVA KGKKQHDKRS DIKEREWQVD KARIMKNAHR