RT83_ECOLX
ID RT83_ECOLX Reviewed; 312 AA.
AC Q47526;
DT 03-AUG-2022, integrated into UniProtKB/Swiss-Prot.
DT 01-NOV-1996, sequence version 1.
DT 03-AUG-2022, entry version 66.
DE RecName: Full=Retron Ec83 reverse transcriptase {ECO:0000303|PubMed:1282191};
DE Short=RT {ECO:0000303|PubMed:1282191};
DE EC=2.7.7.49 {ECO:0000255|PROSITE-ProRule:PRU00405, ECO:0000305|PubMed:1282191};
GN Name=ret {ECO:0000303|PubMed:1282191}; ORFNames=Ga0124318_11281;
OS Escherichia coli.
OC Bacteria; Proteobacteria; Gammaproteobacteria; Enterobacterales;
OC Enterobacteriaceae; Escherichia.
OX NCBI_TaxID=562;
RN [1] {ECO:0000312|EMBL:CAA78293.1}
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA], AND FUNCTION.
RC STRAIN=Clinical strain 161;
RX PubMed=1282191; DOI=10.1111/j.1365-2958.1992.tb01788.x;
RA Lim D.;
RT "Structure and biosynthesis of unbranched multicopy single-stranded DNA by
RT reverse transcriptase in a clinical Escherichia coli isolate.";
RL Mol. Microbiol. 6:3531-3542(1992).
RN [2] {ECO:0000312|EMBL:CXYK01000012}
RP NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC STRAIN=05-2753;
RA Hur Y.J.;
RL Submitted (AUG-2015) to the EMBL/GenBank/DDBJ databases.
RN [3]
RP FUNCTION.
RC STRAIN=Clinical strain 161;
RX PubMed=7885227; DOI=10.1111/j.1365-2958.1994.tb02178.x;
RA Maas W.K., Wang C., Lima T., Zubay G., Lim D.;
RT "Multicopy single-stranded DNAs with mismatched base pairs are mutagenic in
RT Escherichia coli.";
RL Mol. Microbiol. 14:437-441(1994).
RN [4]
RP MATURATION BY EXOVII.
RX PubMed=26626352; DOI=10.1007/s12275-015-5304-0;
RA Jung H., Liang J., Jung Y., Lim D.;
RT "Characterization of cell death in Escherichia coli mediated by XseA, a
RT large subunit of exonuclease VII.";
RL J. Microbiol. 53:820-828(2015).
RN [5]
RP FUNCTION IN ANTIVIRAL DEFENSE, AND INDENTIFICATION AS A RETRON.
RC STRAIN=05-2753;
RX PubMed=33157039; DOI=10.1016/j.cell.2020.09.065;
RA Millman A., Bernheim A., Stokar-Avihail A., Fedorenko T., Voichek M.,
RA Leavitt A., Oppenheimer-Shaanan Y., Sorek R.;
RT "Bacterial Retrons Function In Anti-Phage Defense.";
RL Cell 183:1551-1561(2020).
CC -!- FUNCTION: Reverse transcriptase (RT) component of antiviral defense
CC system retron Ec83, composed of a non-coding RNA (ncRNA), this reverse
CC transcriptase (RT), a probable ATPase and a putative HNH endonuclease.
CC Expression of retron Ec83 confers protection against bacteriophages T2,
CC T4 and T6. At multiplicity of infection (MOI) of 0.02 cultures slow
CC growth when infected with T4 but do not collapse, at MOI 2 cultures
CC enter growth stasis (PubMed:33157039). Responsible for synthesis of
CC msDNA-Ec83 (a linear ssDNA with a 5'-terminal phosphate residue).
CC Unlike most known msDNAs the mature product from the original strain
CC does not have an RNA component. When the ncRNA plus RT are expressed in
CC strain K12 / JM109 only linear DNA is seen in stationary phase cells,
CC but logarithmic phase cells have both a linear and branched msDNA (a
CC branched molecule with RNA linked by a 2',5'-phosphodiester bond to
CC ssDNA, a 'classic' retron). The branched msDNA is probably the
CC precursor for the mature linear msDNA, the precursor is cleaved
CC endonucleolytically by ExoVII (xseA-xseB) leaving the observed mature
CC 5'-phosphate ssDNA terminus. The retron transcript serves as primer
CC (from a conserved internal G residue) and template for the reaction,
CC and codes for the RT (PubMed:1282191, PubMed:26626352). Overexpression
CC of the ncRNA and RT, which leads to increased levels of msDNA, is
CC mutagenic in vivo (PubMed:7885227). This may be due to a mismatch in
CC the msDNA stem which binds and sequesters MutS and/or MutL (Probable).
CC {ECO:0000269|PubMed:1282191, ECO:0000269|PubMed:26626352,
CC ECO:0000269|PubMed:33157039, ECO:0000269|PubMed:7885227,
CC ECO:0000305|PubMed:7885227}.
CC -!- CATALYTIC ACTIVITY:
CC Reaction=a 2'-deoxyribonucleoside 5'-triphosphate + DNA(n) =
CC diphosphate + DNA(n+1); Xref=Rhea:RHEA:22508, Rhea:RHEA-COMP:17339,
CC Rhea:RHEA-COMP:17340, ChEBI:CHEBI:33019, ChEBI:CHEBI:61560,
CC ChEBI:CHEBI:173112; EC=2.7.7.49; Evidence={ECO:0000255|PROSITE-
CC ProRule:PRU00405, ECO:0000305|PubMed:1282191};
CC -!- SIMILARITY: Belongs to the bacterial reverse transcriptase family.
CC {ECO:0000305}.
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DR EMBL; Z12832; CAA78293.1; -; Genomic_DNA.
DR EMBL; CXYK01000012; -; NOT_ANNOTATED_CDS; Genomic_DNA.
DR PIR; S28006; S28006.
DR RefSeq; WP_001403504.1; NZ_WEPV01000028.1.
DR SMR; Q47526; -.
DR GO; GO:0003723; F:RNA binding; IEA:InterPro.
DR GO; GO:0003964; F:RNA-directed DNA polymerase activity; IEA:UniProtKB-KW.
DR CDD; cd03487; RT_Bac_retron_II; 1.
DR InterPro; IPR043502; DNA/RNA_pol_sf.
DR InterPro; IPR000123; Reverse_transcriptase_msDNA.
DR InterPro; IPR000477; RT_dom.
DR Pfam; PF00078; RVT_1; 1.
DR PRINTS; PR00866; RNADNAPOLMS.
DR SUPFAM; SSF56672; SSF56672; 1.
DR PROSITE; PS50878; RT_POL; 1.
PE 1: Evidence at protein level;
KW Antiviral defense; Magnesium; Metal-binding; Nucleotidyltransferase;
KW RNA-binding; RNA-directed DNA polymerase; Transferase.
FT CHAIN 1..312
FT /note="Retron Ec83 reverse transcriptase"
FT /id="PRO_0000456020"
FT DOMAIN 14..239
FT /note="Reverse transcriptase"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00405"
FT BINDING 97
FT /ligand="Mg(2+)"
FT /ligand_id="ChEBI:CHEBI:18420"
FT /ligand_note="catalytic"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00405"
FT BINDING 185
FT /ligand="Mg(2+)"
FT /ligand_id="ChEBI:CHEBI:18420"
FT /ligand_note="catalytic"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00405"
FT BINDING 186
FT /ligand="Mg(2+)"
FT /ligand_id="ChEBI:CHEBI:18420"
FT /ligand_note="catalytic"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00405"
SQ SEQUENCE 312 AA; 35734 MW; 9AEBAD9D1330CBD5 CRC64;
MSIDIETTLQ KAYPDFDVLL KSRPATHYKV YKIPKRTIGY RIIAQPTPRV KAIQRDIIEI
LKQHTHIHDA ATAYVDGKNI LDNAKIHQSS VYLLKLDLVN FFNKITPELL FKALARQKVD
ISDTNKNLLK QFCFWNRTKR KNGALVLSVG APSSPFISNI VMSSFDEEIS SFCKENKISY
SRYADDLTFS TNERDVLGLA HQKVKTTLIR FFGTRIIINN NKIVYSSKAH NRHVTGVTLT
NNNKLSLGRE RKRYITSLVF KFKEGKLSNV DINHLRGLIG FAYNIEPAFI ERLEKKYGES
TIKSIKKYSE GG
