SSRP_AQUAE
ID SSRP_AQUAE Reviewed; 157 AA.
AC O66640;
DT 30-MAY-2000, integrated into UniProtKB/Swiss-Prot.
DT 01-AUG-1998, sequence version 1.
DT 03-AUG-2022, entry version 122.
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}; Synonyms=smb;
GN OrderedLocusNames=aq_287;
OS Aquifex aeolicus (strain VF5).
OC Bacteria; Aquificae; Aquificales; Aquificaceae; Aquifex.
OX NCBI_TaxID=224324;
RN [1]
RP NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC STRAIN=VF5;
RX PubMed=9537320; DOI=10.1038/32831;
RA Deckert G., Warren P.V., Gaasterland T., Young W.G., Lenox A.L.,
RA Graham D.E., Overbeek R., Snead M.A., Keller M., Aujay M., Huber R.,
RA Feldman R.A., Short J.M., Olsen G.J., Swanson R.V.;
RT "The complete genome of the hyperthermophilic bacterium Aquifex aeolicus.";
RL Nature 392:353-358(1998).
RN [2]
RP STRUCTURE BY NMR OF 2-134.
RX PubMed=11927568; DOI=10.1093/emboj/21.7.1845;
RA Dong G., Nowakowski J., Hoffman D.W.;
RT "Structure of small protein B: the protein component of the tmRNA-SmpB
RT system for ribosome rescue.";
RL EMBO J. 21:1845-1854(2002).
RN [3]
RP STRUCTURE BY ELECTRON MICROSCOPY (13.00 ANGSTROMS) OF 2-131.
RX PubMed=12677067; DOI=10.1126/science.1081798;
RA Valle M., Gillet R., Kaur S., Henne A., Ramakrishnan V., Frank J.;
RT "Visualizing tmRNA entry into a stalled ribosome.";
RL Science 300:127-130(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 -!- MISCELLANEOUS: Although the Valle et al., electron microscopy paper
CC indicates this protein came from T.thermophilus its sequence maps to
CC A.aeolicus. {ECO:0000305|PubMed:12677067}.
CC -!- SIMILARITY: Belongs to the SmpB family. {ECO:0000255|HAMAP-
CC Rule:MF_00023}.
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DR EMBL; AE000657; AAC06597.1; -; Genomic_DNA.
DR PIR; D70326; D70326.
DR RefSeq; NP_213200.1; NC_000918.1.
DR RefSeq; WP_010880138.1; NC_000918.1.
DR PDB; 1K8H; NMR; -; A=2-134.
DR PDB; 1P6V; X-ray; 3.20 A; A/C=2-157.
DR PDB; 1ZC8; EM; 13.00 A; K=2-131.
DR PDB; 2OB7; EM; 13.60 A; B/C=2-157.
DR PDBsum; 1K8H; -.
DR PDBsum; 1P6V; -.
DR PDBsum; 1ZC8; -.
DR PDBsum; 2OB7; -.
DR AlphaFoldDB; O66640; -.
DR SMR; O66640; -.
DR STRING; 224324.aq_287; -.
DR EnsemblBacteria; AAC06597; AAC06597; aq_287.
DR KEGG; aae:aq_287; -.
DR PATRIC; fig|224324.8.peg.238; -.
DR eggNOG; COG0691; Bacteria.
DR HOGENOM; CLU_108953_0_1_0; -.
DR InParanoid; O66640; -.
DR OMA; WTNHSAR; -.
DR OrthoDB; 1720952at2; -.
DR EvolutionaryTrace; O66640; -.
DR Proteomes; UP000000798; Chromosome.
DR GO; GO:0005829; C:cytosol; IBA:GO_Central.
DR GO; GO:0003723; F:RNA binding; IBA:GO_Central.
DR GO; GO:0070929; P:trans-translation; IEA:UniProtKB-UniRule.
DR GO; GO:0070930; P:trans-translation-dependent protein tagging; IBA:GO_Central.
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 1: Evidence at protein level;
KW 3D-structure; Cytoplasm; Reference proteome; RNA-binding.
FT CHAIN 1..157
FT /note="SsrA-binding protein"
FT /id="PRO_0000102894"
FT STRAND 7..12
FT /evidence="ECO:0007829|PDB:1P6V"
FT TURN 15..19
FT /evidence="ECO:0007829|PDB:1P6V"
FT STRAND 22..27
FT /evidence="ECO:0007829|PDB:1P6V"
FT HELIX 34..41
FT /evidence="ECO:0007829|PDB:1P6V"
FT STRAND 48..56
FT /evidence="ECO:0007829|PDB:1K8H"
FT STRAND 59..65
FT /evidence="ECO:0007829|PDB:1K8H"
FT STRAND 84..86
FT /evidence="ECO:0007829|PDB:1P6V"
FT HELIX 90..103
FT /evidence="ECO:0007829|PDB:1P6V"
FT STRAND 106..117
FT /evidence="ECO:0007829|PDB:1P6V"
FT STRAND 119..126
FT /evidence="ECO:0007829|PDB:1P6V"
SQ SEQUENCE 157 AA; 18530 MW; FF43E3EF0FD77CFA CRC64;
MGKSDKIIPI AENKEAKAKY DILETYEAGI VLKGSEVKSL REKGTVSFKD SFVRIENGEA
WLYNLYIAPY KHATIENHDP LRKRKLLLHK REIMRLYGKV QEKGYTIIPL KLYWKNNKVK
VLIALAKGKK LYDRRRELKE KAMKRELERE FKGKIHL
