The complete nucleotide sequence of RNa1 of barley mild mosaic virus (asl1) and attempts at bacterial expression of the P3 protein

The complete nucleotide sequence of RNA0 of an Asch! ersleben isolate of barley mild mosaic virus "BaMMV# was determined[ It consists of 6152 nucleotides "nt# excluding the 2? poly "A# tail[ The 4? and 2? nontranslated regions "NTR# are 037 and 227 nt in length\ respectivelyand ~ank a single large open reading frame coding for a precursor polypeptide with a calculated molecular mass of 145 kDa[ Sequence comparison revealed a 85) amino acid "aa# identity to RNA0 translation products of Japanese and French BaMMV isolates[ Conserved nucleotide motifs in the 2? sense and 4? complementary sense NTR of the two genomic RNAs were identi_ed that may represent the polymerase recognition sites[ A range of constructs containing various parts of the coding region of the P2 nonstructural protein was prepared for expression in Escherichia coli[ A short stretch of 24 aa in the C!proximal region of P2 appeared to be highly toxic to the bacterium[