UV laser induced RNA-protein crosslinks and RNA chain breaks in tobacco mosaic virus RNA in situ.

The efficiency of RNA-protein crosslink and RNA chain break formation under nanosecond or picosecond UV-laser pulse irradiation of tobacco mosaic virus was determined. It was found that on high-intensity UV-laser irradiation the quantum yields of both reactions increase considerably as compared to the usual (low-intensity) UV-irradiation. The RNA-protein crosslink quantum yield was found to be 1.8 x 10(-5) and 1.2 x 10(-4) and that of RNA chain breaks 1.7 x 10(-4) and 8.9 x 10(-4) for nanosecond and picosecond irradiation, respectively.