Scientists Discover a Bizarre New Way Life Can Make DNA… Without DNA

Researchers at Columbia University studying the DRT3 immune defense system in Escherichia coli discovered that bacteria can build DNA using a protein as a molecular template instead of the usual nucleic acid template. One reverse transcriptase enzyme copies RNA while another reads amino acids in a protein itself to determine which DNA building blocks are added, with the two resulting strands then pairing to form double-stranded DNA. This reverses the normal flow of biological information from DNA → RNA → protein.