Sequence analysis of the 5' ends of tomato spotted wilt virus N mRNAs

Messenger RNAs transcribed from the tomato spotted wilt virus (TSWV) RNA genome have characteristic extra non-templated heterogeneous sequences at their 5' ends which may be the result of a cap-snatching event involving cellular mRNAs. In order to investigate the genetic origin of these extra sequences and to gain more insight in the process of cap-snatching as performed by TSWV, nucleocapsid protein (N) mRNAs derived from the TSWV S RNA were cloned and sequenced. Twenty clones were obtained which contained 5'-proximal sequences of non-viral origin, ranging in length from 12 to 21 nucleotides. None of the sequences analyzed were identical and no base preference at the endonucleolytic site was observed.