RT73_ECOLX
ID RT73_ECOLX Reviewed; 316 AA.
AC P0DV86;
DT 03-AUG-2022, integrated into UniProtKB/Swiss-Prot.
DT 03-AUG-2022, sequence version 1.
DT 03-AUG-2022, entry version 1.
DE RecName: Full=Retron Ec73 reverse transcriptase {ECO:0000303|PubMed:1712012};
DE Short=RT {ECO:0000303|PubMed:1712012};
DE Short=RT-Ec73 {ECO:0000303|PubMed:1712012};
DE EC=2.7.7.49 {ECO:0000255|PROSITE-ProRule:PRU00405, ECO:0000269|PubMed:7529762};
GN Name=ret {ECO:0000305};
GN ORFNames=Ga0175965_1548, RG59_11970 {ECO:0000303|Ref.2};
OS Escherichia coli.
OC Bacteria; Proteobacteria; Gammaproteobacteria; Enterobacterales;
OC Enterobacteriaceae; Escherichia.
OX NCBI_TaxID=562;
RN [1] {ECO:0000312|EMBL:M64113}
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA], FUNCTION, CATALYTIC ACTIVITY,
RP IDENTIFICATION IN A PROPHAGE, AND DISRUPTION PHENOTYPE.
RC STRAIN=C1-23;
RX PubMed=1712012; DOI=10.1128/jb.173.13.4171-4181.1991;
RA Sun J., Inouye M., Inouye S.;
RT "Association of a retroelement with a P4-like cryptic prophage (retronphage
RT phi R73) integrated into the selenocystyl tRNA gene of Escherichia coli.";
RL J. Bacteriol. 173:4171-4181(1991).
RN [2] {ECO:0000312|EMBL:APL18794.1}
RP NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC STRAIN=M10;
RA Jiang J., Xu Z., Zhou Y., Zhao H., Leung F.C.C.;
RT "Vertical and Horizontal Evolutionary Story implied from E. coli complete
RT genomes.";
RL Submitted (NOV-2014) to the EMBL/GenBank/DDBJ databases.
RN [3]
RP FUNCTION, AND PROPHAGE EXCISION AND REINFECTION.
RC STRAIN=C1-23;
RX PubMed=1709758; DOI=10.1126/science.1709758;
RA Inouye S., Sunshine M.G., Six E.W., Inouye M.;
RT "Retronphage phi R73: an E. coli phage that contains a retroelement and
RT integrates into a tRNA gene.";
RL Science 252:969-971(1991).
RN [4]
RP FUNCTION, AND CATALYTIC ACTIVITY.
RX PubMed=7529762; DOI=10.1074/jbc.270.2.581;
RA Shimamoto T., Inouye M., Inouye S.;
RT "The formation of the 2',5'-phosphodiester linkage in the cDNA priming
RT reaction by bacterial reverse transcriptase in a cell-free system.";
RL J. Biol. Chem. 270:581-588(1995).
RN [5]
RP FUNCTION, DOMAIN, AND RNA-BINDING.
RX PubMed=10531319; DOI=10.1074/jbc.274.44.31236;
RA Inouye S., Hsu M.Y., Xu A., Inouye M.;
RT "Highly specific recognition of primer RNA structures for 2'-OH priming
RT reaction by bacterial reverse transcriptases.";
RL J. Biol. Chem. 274:31236-31244(1999).
RN [6]
RP FUNCTION IN ANTIVIRAL DEFENSE, INDENTIFICATION AS A RETRON, AND MUTAGENESIS
RP OF 189-ASP-ASP-190.
RC STRAIN=M10;
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 Ec73, composed of a non-coding RNA (ncRNA) followed by a
CC ribosyltransferase/DNA-binding protein then a reverse transcriptase
CC (RT). Expression of this retron confers protection against
CC bacteriophages SECphi4, SECphi6, SECphi27 and P1. At multiplicity of
CC infection (MOI) of 0.02 cultures grow normally when infected with
CC SECphi4 without collapsing, at MOI 2 cultures enter growth stasis
CC (PubMed:33157039). Responsible for synthesis of msDNA-Ec73 (a branched
CC molecule with RNA linked by a 2',5'-phosphodiester bond to ssDNA). The
CC retron transcript serves as primer (from a conserved internal G
CC residue) and template for the reaction, and codes for the RT
CC (PubMed:1712012, PubMed:10531319, PubMed:1709758, PubMed:7529762).
CC Recognizes only its cognate RNA as a primer template (PubMed:10531319).
CC {ECO:0000269|PubMed:10531319, ECO:0000269|PubMed:1709758,
CC ECO:0000269|PubMed:1712012, ECO:0000269|PubMed:33157039,
CC ECO:0000269|PubMed:7529762}.
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:0000269|PubMed:7529762};
CC -!- DOMAIN: The C-terminal domain (residue 247-316) is required to
CC recognize RNA. {ECO:0000269|PubMed:10531319}.
CC -!- DISRUPTION PHENOTYPE: Bacteria no longer produce msDNA.
CC {ECO:0000269|PubMed:1712012}.
CC -!- MISCELLANEOUS: Part of pro-retronphage phiR73, which is homologous to
CC bacteriophage P4 (PubMed:1712012). With the help of P2 bacteriophage,
CC is excised and packaged into an infectious virion. Retronphage phiR73
CC can lysogenize a new host strain, reintegrating its genome into the
CC selC gene of the host chromosome and enabling the newly formed lysogens
CC to produce msDNA-Ec73 (PubMed:1709758). {ECO:0000269|PubMed:1709758,
CC ECO:0000269|PubMed:1712012}.
CC -!- SIMILARITY: Belongs to the bacterial reverse transcriptase family.
CC {ECO:0000305}.
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DR EMBL; M64113; -; NOT_ANNOTATED_CDS; Genomic_DNA.
DR EMBL; CP010200; APL18794.1; -; Genomic_DNA.
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..316
FT /note="Retron Ec73 reverse transcriptase"
FT /id="PRO_0000456018"
FT DOMAIN 1..243
FT /note="Reverse transcriptase"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00405"
FT REGION 247..316
FT /note="Necessary and required for recognition and binding
FT of RNA"
FT /evidence="ECO:0000269|PubMed:10531319"
FT BINDING 99
FT /ligand="Mg(2+)"
FT /ligand_id="ChEBI:CHEBI:18420"
FT /ligand_note="catalytic"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00405"
FT BINDING 189
FT /ligand="Mg(2+)"
FT /ligand_id="ChEBI:CHEBI:18420"
FT /ligand_note="catalytic"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00405"
FT BINDING 190
FT /ligand="Mg(2+)"
FT /ligand_id="ChEBI:CHEBI:18420"
FT /ligand_note="catalytic"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00405"
FT MUTAGEN 189..190
FT /note="DD->AA: No longer protects against bacteriophage
FT SECphi4, SECphi6, SECphi27 or P1 infection."
FT /evidence="ECO:0000269|PubMed:33157039"
SQ SEQUENCE 316 AA; 36750 MW; 1B5486E6F253925F CRC64;
MRIYSLIDSQ TLMTKGFASE VMRSPEPPKK WDIAKKKGGM RTIYHPSSKV KLIQYWLMNN
VFSKLPMHNA AYAFVKNRSI KSNALLHAES KNKYYVKIDL KDFFPSIKFT DFEYAFTRYR
DRIEFTTEYD KELLQLIKTI CFISDSTLPI GFPTSPLIAN FVARELDEKL TQKLNAIDKL
NATYTRYADD IIVSTNMKGA SKLILDCFKR TMKEIGPDFK INIKKFKICS ASGGSIVVTG
LKVCHDFHIT LHRSMKDKIR LHLSLLSKGI LKDEDHNKLS GYIAYAKDID PHFYTKLNRK
YFQEIKWIQN LHNKVE
