Ultraviolet effects on biological function of RNA phage MS2

Abstract

Ultraviolet effects on the biological function of MS2 phage were investigated. The adsorption of MS2 phage to the host cells is not affected by ultraviolet irradiation of the phage, but the penetration of phage RNA is reduced. Hydrated uridine was detected in the RNA molecules of ultraviolet-irradiated MS2 phage. The sedimentation patterns of the parental phage RNA molecules extracted from Escherichia coli at 12 min after infection with ultraviolet-irradiated phage are heterogeneous in size. However, ribonuclease-resistant RNA duplex (RF) detectable in cells infected with non-irradiated MS2 phage is not found in these cells. The phage RNA in the cells infected by ultraviolet-irradiated MS2 phage is fragmented into small size molecules even when the infected cells were incubated with chloramphenicol; no degradation of parental phage RNA is observed in cells infected with non-irradiated MS2 phage under the same conditions. Ultraviolet-irradiated MS2 phage also might be able to induce an RNA replicating enzyme (RNA replicase) in the host cells, although the enzymic activity seems to be lower than that induced in the cells infected with non-irradiated MS2 phage.