ID   SSRP_MYCGI              Reviewed;         165 AA.
AC   A4TDF4;
DT   20-MAY-2008, integrated into UniProtKB/Swiss-Prot.
DT   15-MAY-2007, sequence version 1.
DT   28-JAN-2026, entry version 102.
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=Mflv_4446;
OS   Mycolicibacterium gilvum (strain PYR-GCK) (Mycobacterium gilvum (strain
OS   PYR-GCK)).
OC   Bacteria; Bacillati; Actinomycetota; Actinomycetes; Mycobacteriales;
OC   Mycobacteriaceae; Mycolicibacterium.
OX   NCBI_TaxID=350054;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=PYR-GCK;
RG   US DOE Joint Genome Institute;
RA   Copeland A., Lucas S., Lapidus A., Barry K., Detter J.C.,
RA   Glavina del Rio T., Hammon N., Israni S., Dalin E., Tice H., Pitluck S.,
RA   Chain P., Malfatti S., Shin M., Vergez L., Schmutz J., Larimer F., Land M.,
RA   Hauser L., Kyrpides N., Mikhailova N., Miller C., Richardson P.;
RT   "Complete sequence of chromosome of Mycobacterium gilvum PYR-GCK.";
RL   Submitted (APR-2007) to the EMBL/GenBank/DDBJ databases.
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; CP000656; ABP46915.1; -; Genomic_DNA.
DR   AlphaFoldDB; A4TDF4; -.
DR   SMR; A4TDF4; -.
DR   STRING; 350054.Mflv_4446; -.
DR   KEGG; mgi:Mflv_4446; -.
DR   eggNOG; COG0691; Bacteria.
DR   HOGENOM; CLU_108953_2_1_11; -.
DR   OrthoDB; 9805462at2; -.
DR   GO; GO:0005829; C:cytosol; IEA:TreeGrafter.
DR   GO; GO:0003723; F:RNA binding; IEA:UniProtKB-UniRule.
DR   GO; GO:0070929; P:trans-translation; IEA:UniProtKB-UniRule.
DR   GO; GO:0070930; P:trans-translation-dependent protein tagging; IEA:TreeGrafter.
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   NCBIfam; NF003843; PRK05422.1; 1.
DR   NCBIfam; TIGR00086; smpB; 1.
DR   PANTHER; PTHR30308:SF2; SSRA-BINDING PROTEIN; 1.
DR   PANTHER; PTHR30308; TMRNA-BINDING COMPONENT OF TRANS-TRANSLATION TAGGING COMPLEX; 1.
DR   Pfam; PF01668; SmpB; 1.
DR   SUPFAM; SSF74982; Small protein B (SmpB); 1.
DR   PROSITE; PS01317; SSRP; 1.
PE   3: Inferred from homology;
KW   Cytoplasm; RNA-binding.
FT   CHAIN           1..165
FT                   /note="SsrA-binding protein"
FT                   /id="PRO_1000074357"
FT   REGION          135..165
FT                   /note="Disordered"
FT                   /evidence="ECO:0000256|SAM:MobiDB-lite"
FT   COMPBIAS        135..158
FT                   /note="Basic and acidic residues"
FT                   /evidence="ECO:0000256|SAM:MobiDB-lite"
SQ   SEQUENCE   165 AA;  18694 MW;  4902C5CFB23C0325 CRC64;
     MAKKPKSVKD TNNMVVASNR KARHNYSILE TYEAGVALVG TEVKSLRDGT ASLADAFATV
     DDGEIWLRNL HIPEYHHGSW TNHAPRRNRK LLMHRREIDN LVGKIRDGNL TLVPLSLYFT
     GGKVKVELAL ARGKQAHDKR QDMARRDAQR EVTRELGRRV KGMTN
//