Saikia, B.; Requelme Barrios, S.; Carell, T.; Brameyer, S.; Jung, K.

N6-methyladenosine (m6A) is the most abundant internal modification of mRNA in eukaryotes that plays, among other mechanisms, an essential role in virus replication. However, the understanding of m6A RNA modification in prokaryotes, especially in relation to phage replication, is limited. To address this knowledge gap, we investigated the effects of m6A RNA modification on phage replication in two model organisms: Vibrio campbellii BAA-1116 (previously V. harveyi BB120) and Escherichia coli MG1655. An m6A-RNA depleted V. campbellii mutant ({Delta}rlmF{Delta}rlmJ) did not differ from the wild type in the induction of lysogenic phages or in susceptibility to the lytic Virtus phage. In contrast, the infection potential of the T5 phage, but not that of other T phages or the lambda phage, was reduced in an m6A-RNA depleted E. coli mutant ({Delta}rlmF{Delta}rlmJ) compared to the wild type. This was shown by a lower efficiency of plaquing and a higher percentage of surviving cells. There were no differences in T5 phage adsorption rate, but the mutant exhibited a 5 min delay in the rise period during the one-step growth curve. This is the first report demonstrating that E. coli mutant cells with lower m6A RNA levels have a higher chance of surviving T5 phage infection.