ID   SSRP_METCA              Reviewed;         157 AA.
AC   Q604C6;
DT   15-MAR-2005, integrated into UniProtKB/Swiss-Prot.
DT   23-NOV-2004, sequence version 1.
DT   25-MAY-2022, entry version 88.
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=MCA2620;
OS   Methylococcus capsulatus (strain ATCC 33009 / NCIMB 11132 / Bath).
OC   Bacteria; Proteobacteria; Gammaproteobacteria; Methylococcales;
OC   Methylococcaceae; Methylococcus.
OX   NCBI_TaxID=243233;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=ATCC 33009 / NCIMB 11132 / Bath;
RX   PubMed=15383840; DOI=10.1371/journal.pbio.0020303;
RA   Ward N.L., Larsen O., Sakwa J., Bruseth L., Khouri H.M., Durkin A.S.,
RA   Dimitrov G., Jiang L., Scanlan D., Kang K.H., Lewis M.R., Nelson K.E.,
RA   Methe B.A., Wu M., Heidelberg J.F., Paulsen I.T., Fouts D.E., Ravel J.,
RA   Tettelin H., Ren Q., Read T.D., DeBoy R.T., Seshadri R., Salzberg S.L.,
RA   Jensen H.B., Birkeland N.K., Nelson W.C., Dodson R.J., Grindhaug S.H.,
RA   Holt I.E., Eidhammer I., Jonasen I., Vanaken S., Utterback T.R.,
RA   Feldblyum T.V., Fraser C.M., Lillehaug J.R., Eisen J.A.;
RT   "Genomic insights into methanotrophy: the complete genome sequence of
RT   Methylococcus capsulatus (Bath).";
RL   PLoS Biol. 2:1616-1628(2004).
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; AE017282; AAU91279.1; -; Genomic_DNA.
DR   RefSeq; WP_010961833.1; NC_002977.6.
DR   AlphaFoldDB; Q604C6; -.
DR   SMR; Q604C6; -.
DR   STRING; 243233.MCA2620; -.
DR   EnsemblBacteria; AAU91279; AAU91279; MCA2620.
DR   KEGG; mca:MCA2620; -.
DR   eggNOG; COG0691; Bacteria.
DR   HOGENOM; CLU_108953_3_0_6; -.
DR   OMA; WTNHSAR; -.
DR   OrthoDB; 1720952at2; -.
DR   Proteomes; UP000006821; 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..157
FT                   /note="SsrA-binding protein"
FT                   /id="PRO_0000102978"
FT   REGION          128..157
FT                   /note="Disordered"
FT                   /evidence="ECO:0000256|SAM:MobiDB-lite"
SQ   SEQUENCE   157 AA;  17931 MW;  6AD7911A2119547A CRC64;
     MSSKKSAPGS ANIAQNRQAT HEYFIEERLE AGLVLEGWEV KSLRAGKAQL KESFVMLKNG
     EAWLFGAHFS PLPSASTHVQ PDPTRSRKLL LHAEELSRLI GQVERKGYTL VPLSLYWKQG
     RAKLEIGLAR GKKQHDKRAA EKERDWEREK QRVMRRG