ID   SSRP_RICPR              Reviewed;         152 AA.
AC   O05968;
DT   15-JUL-1998, integrated into UniProtKB/Swiss-Prot.
DT   01-JUL-1997, sequence version 1.
DT   25-MAY-2022, entry version 109.
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=RP430;
OS   Rickettsia prowazekii (strain Madrid E).
OC   Bacteria; Proteobacteria; Alphaproteobacteria; Rickettsiales;
OC   Rickettsiaceae; Rickettsieae; Rickettsia; typhus group.
OX   NCBI_TaxID=272947;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RC   STRAIN=Madrid E;
RX   PubMed=9274032; DOI=10.1099/00221287-143-8-2783;
RA   Andersson J.O., Andersson S.G.E.;
RT   "Genomic rearrangements during evolution of the obligate intracellular
RT   parasite Rickettsia prowazekii as inferred from an analysis of 52015 bp
RT   nucleotide sequence.";
RL   Microbiology 143:2783-2795(1997).
RN   [2]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=Madrid E;
RX   PubMed=9823893; DOI=10.1038/24094;
RA   Andersson S.G.E., Zomorodipour A., Andersson J.O., Sicheritz-Ponten T.,
RA   Alsmark U.C.M., Podowski R.M., Naeslund A.K., Eriksson A.-S., Winkler H.H.,
RA   Kurland C.G.;
RT   "The genome sequence of Rickettsia prowazekii and the origin of
RT   mitochondria.";
RL   Nature 396:133-140(1998).
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}.
CC   -!- CAUTION: SsrA has yet not been found in R.prowazekii, so the function
CC       of this protein is not obvious. {ECO:0000305}.
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DR   EMBL; Y11777; CAA72448.1; -; Genomic_DNA.
DR   EMBL; AJ235271; CAA14887.1; -; Genomic_DNA.
DR   PIR; E71701; E71701.
DR   RefSeq; NP_220811.1; NC_000963.1.
DR   RefSeq; WP_004599469.1; NC_000963.1.
DR   AlphaFoldDB; O05968; -.
DR   SMR; O05968; -.
DR   STRING; 272947.RP430; -.
DR   EnsemblBacteria; CAA14887; CAA14887; CAA14887.
DR   GeneID; 57569555; -.
DR   KEGG; rpr:RP430; -.
DR   PATRIC; fig|272947.5.peg.443; -.
DR   eggNOG; COG0691; Bacteria.
DR   HOGENOM; CLU_108953_0_0_5; -.
DR   OMA; WTNHSAR; -.
DR   Proteomes; UP000002480; 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; Reference proteome; RNA-binding.
FT   CHAIN           1..152
FT                   /note="SsrA-binding protein"
FT                   /id="PRO_0000103018"
SQ   SEQUENCE   152 AA;  17770 MW;  09C99FE05DDF3C1D CRC64;
     MIEDKKVIVQ NKKALFNYFI EEILEAGIVL KGSEVQSLRQ GKASIEESHA SDNGHEVFLY
     NCHITEYEKA NRFNHSTRRP RKLLLHAKEI KKIIGRIRIK GYTLVALSMY FNKKNKVKVE
     LGIAKGKKLY DKRAAIKEKD WKKDQSRLIR QK