Reverse transcriptase (RT) component of antiviral defense system retron Ec83, composed of a non-coding RNA (ncRNA), this reverse transcriptase (RT), a probable ATPase and a putative HNH endonuclease. Expression of retron Ec83 confers protection against bacteriophages T2, T4 and T6. At multiplicity of infection (MOI) of 0.02 cultures slow growth when infected with T4 but do not collapse, at MOI 2 cultures enter growth stasis (PubMed:33157039). Responsible for synthesis of msDNA-Ec83 (a linear ssDNA with a 5'-terminal phosphate residue). Unlike most known msDNAs the mature product from the original strain does not have an RNA component. When the ncRNA plus RT are expressed in strain K12 / JM109 only linear DNA is seen in stationary phase cells, but logarithmic phase cells have both a linear and branched msDNA (a branched molecule with RNA linked by a 2',5'-phosphodiester bond to ssDNA, a 'classic' retron). The branched msDNA is probably the precursor for the mature linear msDNA, the precursor is cleaved endonucleolytically by ExoVII (xseA-xseB) leaving the observed mature 5'-phosphate ssDNA terminus. The retron transcript serves as primer (from a conserved internal G residue) and template for the reaction, and codes for the RT (PubMed:1282191, PubMed:26626352). Overexpression of the ncRNA and RT, which leads to increased levels of msDNA, is mutagenic in vivo (PubMed:7885227). This may be due to a mismatch in the msDNA stem which binds and sequesters MutS and/or MutL (Probable). a 2'-deoxyribonucleoside 5'-triphosphate + DNA(n) = diphosphate + DNA(n+1) Belongs to the bacterial reverse transcriptase family.