ID   SSRP_MYCPN              Reviewed;         147 AA.
AC   P75043;
DT   01-NOV-1997, integrated into UniProtKB/Swiss-Prot.
DT   01-FEB-1997, sequence version 1.
DT   03-AUG-2022, entry version 110.
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=MPN_074;
GN   ORFNames=MP081;
OS   Mycoplasma pneumoniae (strain ATCC 29342 / M129) (Mycoplasmoides
OS   pneumoniae).
OC   Bacteria; Tenericutes; Mollicutes; Mycoplasmataceae; Mycoplasma.
OX   NCBI_TaxID=272634;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=ATCC 29342 / M129;
RX   PubMed=8948633; DOI=10.1093/nar/24.22.4420;
RA   Himmelreich R., Hilbert H., Plagens H., Pirkl E., Li B.-C., Herrmann R.;
RT   "Complete sequence analysis of the genome of the bacterium Mycoplasma
RT   pneumoniae.";
RL   Nucleic Acids Res. 24:4420-4449(1996).
RN   [2]
RP   DISRUPTION PHENOTYPE.
RC   STRAIN=ATCC 29342 / M129;
RX   PubMed=10591650; DOI=10.1126/science.286.5447.2165;
RA   Hutchison C.A., Peterson S.N., Gill S.R., Cline R.T., White O.,
RA   Fraser C.M., Smith H.O., Venter J.C.;
RT   "Global transposon mutagenesis and a minimal Mycoplasma genome.";
RL   Science 286:2165-2169(1999).
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   -!- DISRUPTION PHENOTYPE: May not be essential, 1 disruption mutant has
CC       been isolated. {ECO:0000269|PubMed:10591650}.
CC   -!- SIMILARITY: Belongs to the SmpB family. {ECO:0000255|HAMAP-
CC       Rule:MF_00023}.
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DR   EMBL; U00089; AAB95729.1; -; Genomic_DNA.
DR   PIR; S73407; S73407.
DR   RefSeq; NP_109762.1; NC_000912.1.
DR   AlphaFoldDB; P75043; -.
DR   SMR; P75043; -.
DR   STRING; 272634.MPN_074; -.
DR   EnsemblBacteria; AAB95729; AAB95729; MPN_074.
DR   KEGG; mpn:MPN_074; -.
DR   PATRIC; fig|272634.6.peg.75; -.
DR   HOGENOM; CLU_108953_0_1_14; -.
DR   OMA; WTNHSAR; -.
DR   BioCyc; MPNE272634:G1GJ3-112-MON; -.
DR   Proteomes; UP000000808; 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..147
FT                   /note="SsrA-binding protein"
FT                   /id="PRO_0000102989"
SQ   SEQUENCE   147 AA;  17087 MW;  6F4AF3E5A4412C40 CRC64;
     MRVLVNNPRA QYDYYLLTGY CAGLVLKGSE VKSLALGQGS LKEAYVFIDK HEVYIKDFSI
     SPYAFSGEFN HPFKRVKKLL LNRNEIKQIT ARQKQEGLSI IPLKVFFKNG KIKMEIWLAK
     PKKKFDKREA IKSKTIQREL RQQYGSP