SSRP_PROMM
ID SSRP_PROMM Reviewed; 165 AA.
AC Q7V911;
DT 15-DEC-2003, integrated into UniProtKB/Swiss-Prot.
DT 01-OCT-2003, sequence version 1.
DT 25-MAY-2022, entry version 94.
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=PMT_0155;
OS Prochlorococcus marinus (strain MIT 9313).
OC Bacteria; Cyanobacteria; Synechococcales; Prochlorococcaceae;
OC Prochlorococcus.
OX NCBI_TaxID=74547;
RN [1]
RP NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC STRAIN=MIT 9313;
RX PubMed=12917642; DOI=10.1038/nature01947;
RA Rocap G., Larimer F.W., Lamerdin J.E., Malfatti S., Chain P., Ahlgren N.A.,
RA Arellano A., Coleman M., Hauser L., Hess W.R., Johnson Z.I., Land M.L.,
RA Lindell D., Post A.F., Regala W., Shah M., Shaw S.L., Steglich C.,
RA Sullivan M.B., Ting C.S., Tolonen A., Webb E.A., Zinser E.R.,
RA Chisholm S.W.;
RT "Genome divergence in two Prochlorococcus ecotypes reflects oceanic niche
RT differentiation.";
RL Nature 424:1042-1047(2003).
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; BX548175; CAE20330.1; -; Genomic_DNA.
DR RefSeq; WP_011129533.1; NC_005071.1.
DR AlphaFoldDB; Q7V911; -.
DR SMR; Q7V911; -.
DR STRING; 74547.PMT_0155; -.
DR EnsemblBacteria; CAE20330; CAE20330; PMT_0155.
DR KEGG; pmt:PMT_0155; -.
DR eggNOG; COG0691; Bacteria.
DR HOGENOM; CLU_108953_0_1_3; -.
DR OMA; WTNHSAR; -.
DR OrthoDB; 1720952at2; -.
DR Proteomes; UP000001423; 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..165
FT /note="SsrA-binding protein"
FT /id="PRO_0000103006"
FT REGION 141..165
FT /note="Disordered"
FT /evidence="ECO:0000256|SAM:MobiDB-lite"
SQ SEQUENCE 165 AA; 18615 MW; 3A654EAA8D6359FE CRC64;
MAKGGNKKAT AAARAAANRL LADNRLARHQ YEILDTLETG IELVGTEVKS IRAGQANLRD
GFCLIRKGEL QLHNVHISPH SHAGSYFNHD PLRTRKLLAH RREIDKLRGQ LDRKGLTLIP
LNLHLKGSWI KLTIGLGKGR KLHDKRQDEK RKQADREVKS ALARY
