Although most of the people connect mentally, Reverse Transcriptase (RTase) is only found in viruses,presence of this enzyme in some pathogenic bacteria has raised question-Is there any evolutionary relationship between Viruses and Bacteria? The enzyme has found to synthesize a special satellite DNA called msDNA (Multicopy Single-Stranded DNA) from an especial genomic segment called Retron. This satellite DNA caught researchers´ attention because of it´s strange structure, which consisted of a single-stranded DNA molecule linked with branched RNA through phosphodiester bond. Despite considerable investigation, very little is known about the function of msDNA, the mobility of retron elements, or their effect on the host cell.Here, we discussed our complete findings on Retron-Yf79 and its especial product msDNA-Yf79 in Yersinia frederiksenii.The retron-Yf79 was a foreign DNA element and integrated into this organism genome during their evolution. In addition we discovered transposase gene at downstream of Retron-Yf79 which might helps transposition of this transposable element.Further clinical significance of research into this area would help to understand bacterial pathogenicity.