SSRP_PROMP
ID SSRP_PROMP Reviewed; 175 AA.
AC Q7UZP2;
DT 15-DEC-2003, integrated into UniProtKB/Swiss-Prot.
DT 01-OCT-2003, sequence version 1.
DT 25-MAY-2022, entry version 91.
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=PMM1616;
OS Prochlorococcus marinus subsp. pastoris (strain CCMP1986 / NIES-2087 /
OS MED4).
OC Bacteria; Cyanobacteria; Synechococcales; Prochlorococcaceae;
OC Prochlorococcus.
OX NCBI_TaxID=59919;
RN [1]
RP NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC STRAIN=CCMP1986 / NIES-2087 / MED4;
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}.
CC ---------------------------------------------------------------------------
CC Copyrighted by the UniProt Consortium, see https://www.uniprot.org/terms
CC Distributed under the Creative Commons Attribution (CC BY 4.0) License
CC ---------------------------------------------------------------------------
DR EMBL; BX548174; CAE20075.1; -; Genomic_DNA.
DR AlphaFoldDB; Q7UZP2; -.
DR SMR; Q7UZP2; -.
DR STRING; 59919.PMM1616; -.
DR EnsemblBacteria; CAE20075; CAE20075; PMM1616.
DR KEGG; pmm:PMM1616; -.
DR eggNOG; COG0691; Bacteria.
DR HOGENOM; CLU_108953_0_1_3; -.
DR OMA; WTNHSAR; -.
DR Proteomes; UP000001026; 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; RNA-binding.
FT CHAIN 1..175
FT /note="SsrA-binding protein"
FT /id="PRO_0000103007"
SQ SEQUENCE 175 AA; 20283 MW; 781EB09DEBC5EC62 CRC64;
MFFGERFFTT AMAKVSNKAN KIIKKEAVFK RLSENRYAKF QYEILETIEA GIELLGTEVK
SIRNGSVNLR DGYCSFRDGE ILLLNVHISP HKNVGPFFNH DPLRNRKLLL HKKEIVKLKY
NTEKKGLTII PLSIYLKGSW IKLTIGIGKG KKLHDKRQAD KQRDIKREIK TALKR
