Yan-Jiun Lee, Nan Dai, Stephanie I Müller, Chudi Guan, Mackenzie J Parker, Morgan E Fraser, Shannon E Walsh, Janani Sridar, Andrew Mulholland, Krutika Nayak, Zhiyi Sun, Yu-Cheng Lin, Donald G Comb, Katherine Marks, Reyaz Gonzalez, Daniel P Dowling, Vahe Bandarian, Lana Saleh, Ivan R Corrêa, Jr, and Peter R Weigele
Nucleic Acids Research, gkab1064, doi:10.1093/nar/gkab1064
Viruses that infect bacteria (bacteriophages) are everywhere life is found. These deadly molecular machines inject DNA into their bacterial hosts, instructing them to make more bacteriophages. As a defense, bacteria evolved “molecular scissors”– enzymes that can snip invading DNA and stop the infection. The authors have now determined the pathways by which some bacteriophages fight back to evade their hosts’ defenses. Their work shows that enzymes encoded by bacteriophages catalyze the attachment of amino acids and other molecules to DNA. These modifications act as a shield against the molecular scissors making the DNA resistant to cleavage. Since amino acids normally function in proteins, this result is surprising and suggests a chemical diversity of modifications on A,G,C and T that awaits further exploration. The bacteriophage DNA modifying enzymes discovered in this study might one day be harnessed to anchor DNA on chips, label DNA with fluorescent dyes and much more.