RT48_ECOLX
ID RT48_ECOLX Reviewed; 408 AA.
AC P71276;
DT 03-AUG-2022, integrated into UniProtKB/Swiss-Prot.
DT 03-AUG-2022, sequence version 2.
DT 03-AUG-2022, entry version 63.
DE RecName: Full=Retron Ec48 reverse transcriptase {ECO:0000303|PubMed:9401048};
DE Short=RT-Ec48 {ECO:0000303|PubMed:9401048};
DE EC=2.7.7.49 {ECO:0000255|PROSITE-ProRule:PRU00405, ECO:0000305|PubMed:8878541};
DE AltName: Full=ECOR-58 reverse transcriptase {ECO:0000303|PubMed:8878541};
GN Name=ret {ECO:0000305};
GN ORFNames=ERS085376_00284 {ECO:0000303|Ref.2}, Ga0119542_1001285;
OS Escherichia coli.
OC Bacteria; Proteobacteria; Gammaproteobacteria; Enterobacterales;
OC Enterobacteriaceae; Escherichia.
OX NCBI_TaxID=562;
RN [1] {ECO:0000312|EMBL:AAB70880.1}
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA], AND FUNCTION.
RC STRAIN=ATCC 35377 / ECOR 58;
RX PubMed=8878541; DOI=10.1006/bbrc.1996.1534;
RA Mao J.R., Inouye M., Inouye S.;
RT "An unusual bacterial reverse transcriptase having LVDD in the YXDD box
RT from Escherichia coli.";
RL Biochem. Biophys. Res. Commun. 227:489-493(1996).
RN [2] {ECO:0000312|EMBL:CTR27268.1}
RP NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC STRAIN=700337;
RG Pathogen Informatics;
RL Submitted (AUG-2015) to the EMBL/GenBank/DDBJ databases.
RN [3]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA] OF 1-31, AND FUNCTION.
RC STRAIN=ATCC 35377 / ECOR 58;
RX PubMed=9401048; DOI=10.1128/jb.179.24.7865-7868.1997;
RA Mao J.R., Inouye S., Inouye M.;
RT "msDNA-Ec48, the smallest multicopy single-stranded DNA from Escherichia
RT coli.";
RL J. Bacteriol. 179:7865-7868(1997).
RN [4]
RP FUNCTION IN ANTIVIRAL DEFENSE, INDENTIFICATION AS A RETRON, AND MUTAGENESIS
RP OF 216-ASP-ASP-217.
RC STRAIN=700337;
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 Ec48, composed of a non-coding RNA (ncRNA), this reverse
CC transcriptase (RT) and the following membrane protein. Expression of
CC this retron confers protection against bacteriophages lambda, T2, T4,
CC T5 and T7. At multiplicity of infection (MOI) of 0.02 cultures grow
CC normally when infected with lambda without collapsing, at MOI 2
CC cultures enter growth stasis. At MOI 3 cell membranes are permeabilized
CC within 15 minutes of infection but do not lyse, suggesting the phage
CC are not able to finish a replication cycle. Antiviral defense is
CC suppressed by mutations that knockout the lambda gam expression or
CC phage T7 gp5.9 expression; both viral genes inhibit host RecBCD
CC (PubMed:33157039). The Ec48 retron may sense the integrity of the
CC RecBCD enzyme; when RecBCD is perturbed by viral proteins the Ec48
CC effector (the membrane protein) is activated, leading to abortive
CC infection and bacterial growth arrest (Probable). Responsible for
CC synthesis of msDNA-Ec48 (a branched molecule with RNA linked by a
CC 2',5'-phosphodiester bond to ssDNA). The retron transcript serves as
CC primer (from a conserved internal G residue) and template for the
CC reaction, and codes for the RT (PubMed:8878541, PubMed:9401048).
CC {ECO:0000269|PubMed:33157039, ECO:0000269|PubMed:8878541,
CC ECO:0000269|PubMed:9401048, ECO:0000305|PubMed:33157039}.
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:8878541};
CC -!- SIMILARITY: Belongs to the bacterial reverse transcriptase family.
CC {ECO:0000305}.
CC -!- SEQUENCE CAUTION:
CC Sequence=CTR27268.1; Type=Erroneous initiation; Note=Truncated N-terminus.; Evidence={ECO:0000305};
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DR EMBL; U66703; AAB70880.1; -; Genomic_DNA.
DR EMBL; CXZM01000001; CTR27268.1; ALT_INIT; Genomic_DNA.
DR PIR; JC5244; JC5244.
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; IPR001387; Cro/C1-type_HTH.
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..408
FT /note="Retron Ec48 reverse transcriptase"
FT /id="PRO_0000456017"
FT DOMAIN 43..269
FT /note="Reverse transcriptase"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00405"
FT BINDING 137
FT /ligand="Mg(2+)"
FT /ligand_id="ChEBI:CHEBI:18420"
FT /ligand_note="catalytic"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00405"
FT BINDING 216
FT /ligand="Mg(2+)"
FT /ligand_id="ChEBI:CHEBI:18420"
FT /ligand_note="catalytic"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00405"
FT BINDING 217
FT /ligand="Mg(2+)"
FT /ligand_id="ChEBI:CHEBI:18420"
FT /ligand_note="catalytic"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00405"
FT MUTAGEN 216..217
FT /note="DD->AA: No longer protects against infection by
FT lambda, T2, T4, T5 or T7."
FT /evidence="ECO:0000269|PubMed:33157039"
FT CONFLICT 52
FT /note="P -> S (in Ref. 1; AAB70880)"
FT /evidence="ECO:0000305"
FT CONFLICT 250
FT /note="R -> H (in Ref. 1; AAB70880)"
FT /evidence="ECO:0000305"
FT CONFLICT 324
FT /note="A -> G (in Ref. 1; AAB70880)"
FT /evidence="ECO:0000305"
SQ SEQUENCE 408 AA; 46978 MW; C5D24691A073E1E9 CRC64;
MGRPYVTLNL NGMFMDKFKP YSKSNAPITT LEKLSKALSI SVEELKAIAE LPLDEKYTLK
EIPKIDGSKR IVYSLHPKMR LLQSRINKRI FKELVVFPSF LFGSVPSKND VLNSNVKRDY
VSCAKAHCGA KTVLKVDISN FFDNIHRDLV RSVFEEILHI KDEALEYLVD ICTKDDFVVQ
GALTSSYIAT LCLFAVEGDV VRRAQRKGLV YTRLVDDITV SSKISNYDFS QMQSHIERML
SEHDLPINKR KTKIFHCSSE PIKVHGLRVD YDSPRLPSDE VKRIRASIHN LKLLAAKNNT
KTSVAYRKEF NRCMGRVNKL GRVAHEKYES FKKQLQAIKP MPSKRDVAVI DAAIKSLELS
YSKGNQNKHW YKRKYDLTRY KMIILTRSES FKEKLECFKS RLASLKPL
