Reverse transcriptase (RT) component of antiviral defense system retron Se72, composed of a non-coding RNA (ncRNA), this reverse transcriptase (RT) and the following cold shock-like protein. Expression of retron Se72 confers protection against bacteriophage lambda. At multiplicity of infection (MOI) of 0.02 cultures slow growth when infected with lambda but do not collapse, 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 (By similarity). The DNA segment is predicted to be 72 bases long (Probable). a 2'-deoxyribonucleoside 5'-triphosphate + DNA(n) = diphosphate + DNA(n+1) Belongs to the bacterial reverse transcriptase family.