RT86_ECOLX
ID RT86_ECOLX Reviewed; 320 AA.
AC P23070;
DT 01-NOV-1991, integrated into UniProtKB/Swiss-Prot.
DT 01-NOV-1991, sequence version 1.
DT 03-AUG-2022, entry version 76.
DE RecName: Full=Retron Ec86 reverse transcriptase {ECO:0000303|PubMed:33157039};
DE Short=Ec86-RT;
DE EC=2.7.7.49 {ECO:0000269|PubMed:2466573};
DE AltName: Full=ORF320 {ECO:0000303|PubMed:2466573};
DE AltName: Full=Reverse transcriptase {ECO:0000303|PubMed:2466573};
DE Short=RT {ECO:0000303|PubMed:33157039};
GN Name=ret {ECO:0000303|PubMed:1722556}; ORFNames=LM2_00877;
OS Escherichia coli.
OC Bacteria; Proteobacteria; Gammaproteobacteria; Enterobacterales;
OC Enterobacteriaceae; Escherichia.
OX NCBI_TaxID=562;
RN [1] {ECO:0000312|EMBL:AAA61471.1}
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA], FUNCTION, AND CATALYTIC ACTIVITY.
RC STRAIN=B / AC2514;
RX PubMed=2466573; DOI=10.1016/0092-8674(89)90693-4;
RA Lim D., Maas W.K.;
RT "Reverse transcriptase-dependent synthesis of a covalently linked, branched
RT DNA-RNA compound in E. coli B.";
RL Cell 56:891-904(1989).
RN [2] {ECO:0000312|EMBL:CAB56781.1}
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RC STRAIN=B / AC2514;
RX PubMed=1722556; DOI=10.1111/j.1365-2958.1991.tb00810.x;
RA Lim D.;
RT "Structure of two retrons of Escherichia coli and their common chromosomal
RT insertion site.";
RL Mol. Microbiol. 5:1863-1872(1991).
RN [3]
RP FUNCTION, AND DISRUPTION PHENOTYPE.
RC STRAIN=B / AC2514;
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 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 [5]
RP FUNCTION IN ANTIVIRAL DEFENSE, AND INDENTIFICATION AS A RETRON.
RC STRAIN=BL21 (DE3);
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 Ec86, composed of a non-coding RNA (ncRNA), a
CC ribosyltransferase/DNA-binding protein and this RT. Expression of the
CC 3-gene retron confers protection against bacteriophage T5. At
CC multiplicity of infection (MOI) of 0.02 cultures grow normally when
CC infected with T5 without collapsing, at MOI 2 cultures enter growth
CC stasis (PubMed:33157039). Responsible for synthesis of msDNA (a
CC branched molecule with RNA linked by a 2',5'-phosphodiester bond to
CC ssDNA). The retron transcript serves as primer (from a conserved
CC internal G residue) and template for the reaction, and codes for the RT
CC (PubMed:2466573, PubMed:10531319). Recognizes only its cognate RNA as a
CC primer template (PubMed:10531319). Overexpression of the ncRNA and RT
CC (without the ribosyltransferase), which leads to increased levels of
CC msDNA, is mutagenic in vivo (PubMed:7885227). This may be due to a
CC mismatch in the msDNA stem which binds and sequesters MutS and/or MutL
CC (Probable). {ECO:0000269|PubMed:10531319, ECO:0000269|PubMed:2466573,
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:0000269|PubMed:2466573};
CC -!- DOMAIN: The C-terminal domain (residues 230-320) is required to
CC recognize and bind RNA; recognition of cognate RNA also requires a
CC region closer to the N-terminus. {ECO:0000269|PubMed:10531319}.
CC -!- DISRUPTION PHENOTYPE: Loss of expression of msDNA, no longer mutagenic
CC (when overexpressed). {ECO:0000269|PubMed:7885227}.
CC -!- MISCELLANEOUS: Retrons may be the ancestors of retrovirus.
CC -!- SIMILARITY: Belongs to the bacterial reverse transcriptase family.
CC {ECO:0000305}.
CC -!- CAUTION: DNA from strain B / AC2514 has genes in the order
CC ribosyltransferase-ncRNA-RT (PubMed:2466573, PubMed:1722556). The data
CC presented in Millman et al., says genes are encoded in the order ncRNA-
CC ribosyltransferase-RT. {ECO:0000269|PubMed:1722556,
CC ECO:0000269|PubMed:2466573, ECO:0000305|PubMed:33157039}.
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; M24408; AAA61471.1; -; Genomic_DNA.
DR EMBL; X60206; CAB56781.1; -; Genomic_DNA.
DR PIR; A31498; RREC.
DR RefSeq; WP_001320043.1; NZ_WOEL01000022.1.
DR AlphaFoldDB; P23070; -.
DR SMR; P23070; -.
DR PATRIC; fig|562.7299.peg.902; -.
DR OMA; TIYHRIL; -.
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;
KW Transposable element.
FT CHAIN 1..320
FT /note="Retron Ec86 reverse transcriptase"
FT /id="PRO_0000097509"
FT DOMAIN 34..248
FT /note="Reverse transcriptase"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00405"
FT REGION 230..320
FT /note="Necessary and required for recognition and binding
FT of RNA"
FT /evidence="ECO:0000269|PubMed:10531319"
FT BINDING 119
FT /ligand="Mg(2+)"
FT /ligand_id="ChEBI:CHEBI:18420"
FT /ligand_note="catalytic"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00405"
FT BINDING 197
FT /ligand="Mg(2+)"
FT /ligand_id="ChEBI:CHEBI:18420"
FT /ligand_note="catalytic"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00405"
FT BINDING 198
FT /ligand="Mg(2+)"
FT /ligand_id="ChEBI:CHEBI:18420"
FT /ligand_note="catalytic"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00405"
SQ SEQUENCE 320 AA; 36424 MW; 80DA4A993DF381C9 CRC64;
MKSAEYLNTF RLRNLGLPVM NNLHDMSKAT RISVETLRLL IYTADFRYRI YTVEKKGPEK
RMRTIYQPSR ELKALQGWVL RNILDKLSSS PFSIGFEKHQ SILNNATPHI GANFILNIDL
EDFFPSLTAN KVFGVFHSLG YNRLISSVLT KICCYKNLLP QGAPSSPKLA NLICSKLDYR
IQGYAGSRGL IYTRYADDLT LSAQSMKKVV KARDFLFSII PSEGLVINSK KTCISGPRSQ
RKVTGLVISQ EKVGIGREKY KEIRAKIHHI FCGKSSEIEH VRGWLSFILS VDSKSHRRLI
TYISKLEKKY GKNPLNKAKT
