Reverse transcriptase (RT) component of antiviral defense system retron Ec86, composed of a non-coding RNA (ncRNA), a ribosyltransferase/DNA-binding protein and this RT. Expression of the 3-gene retron confers protection against bacteriophage T5. At multiplicity of infection (MOI) of 0.02 cultures grow normally when infected with T5 without collapsing, at MOI 2 cultures enter growth stasis (PubMed:33157039). Responsible for synthesis of msDNA (a branched molecule with RNA linked by a 2',5'-phosphodiester bond to ssDNA). The retron transcript serves as primer (from a conserved internal G residue) and template for the reaction, and codes for the RT (PubMed:2466573, PubMed:10531319). Recognizes only its cognate RNA as a primer template (PubMed:10531319). Overexpression of the ncRNA and RT (without the ribosyltransferase), 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) The C-terminal domain (residues 230-320) is required to recognize and bind RNA; recognition of cognate RNA also requires a region closer to the N-terminus. Loss of expression of msDNA, no longer mutagenic (when overexpressed). Retrons may be the ancestors of retrovirus. Belongs to the bacterial reverse transcriptase family. DNA from strain B / AC2514 has genes in the order ribosyltransferase-ncRNA-RT (PubMed:2466573, PubMed:1722556). The data presented in Millman et al., says genes are encoded in the order ncRNA-ribosyltransferase-RT.