ID   SSRP_GLOC7              Reviewed;         155 AA.
AC   B7KF17;
DT   14-APR-2009, integrated into UniProtKB/Swiss-Prot.
DT   10-FEB-2009, sequence version 1.
DT   03-AUG-2022, entry version 67.
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=PCC7424_2045;
OS   Gloeothece citriformis (strain PCC 7424) (Cyanothece sp. (strain PCC
OS   7424)).
OC   Bacteria; Cyanobacteria; Oscillatoriophycideae; Chroococcales;
OC   Aphanothecaceae; Gloeothece; Gloeothece citriformis.
OX   NCBI_TaxID=65393;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=PCC 7424;
RX   PubMed=21972240; DOI=10.1128/mbio.00214-11;
RA   Bandyopadhyay A., Elvitigala T., Welsh E., Stockel J., Liberton M., Min H.,
RA   Sherman L.A., Pakrasi H.B.;
RT   "Novel metabolic attributes of the genus Cyanothece, comprising a group of
RT   unicellular nitrogen-fixing Cyanobacteria.";
RL   MBio 2:E214-E214(2011).
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; CP001291; ACK70473.1; -; Genomic_DNA.
DR   RefSeq; WP_015954079.1; NC_011729.1.
DR   AlphaFoldDB; B7KF17; -.
DR   SMR; B7KF17; -.
DR   STRING; 65393.PCC7424_2045; -.
DR   EnsemblBacteria; ACK70473; ACK70473; PCC7424_2045.
DR   KEGG; cyc:PCC7424_2045; -.
DR   eggNOG; COG0691; Bacteria.
DR   HOGENOM; CLU_108953_0_1_3; -.
DR   OMA; WTNHSAR; -.
DR   OrthoDB; 1720952at2; -.
DR   Proteomes; UP000002384; 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..155
FT                   /note="SsrA-binding protein"
FT                   /id="PRO_1000116418"
SQ   SEQUENCE   155 AA;  18210 MW;  E64102A81803C3A6 CRC64;
     MSNQNGKTKL ITDNRQARFL YEILETYEAG IELTGTEVKS IRAGRINLKD GYALIRNGEA
     WLINVHISPY EASGQYFNHD PRRTRKLLLH RKEINKLIGQ VEQKGLTLVP LKMYFKDSWV
     KVSIGLAQGK KLHDKRETLK RRQDERDMQR AMKRW