Complete nucleotide sequence and genome organization of tobacco mosaic virus isolated from Vicia faba

Based on reported TMV-UI sequence, primers were designed and fragments cove ring the entire genome of TMV broad bean strain (TMV-B) were obtained with RT-PCR. These fragments were cloned and sequenced and the 5' and 3' end seq uences of genome were confirmed with RACE. The complete sequence of TMV-B c omprises 6 395 nucleotides (nt) and four open reading frames, which corresp ond to 126 ku (1 116 amino acids), 183 ku (1 616 amino acids), 30 ku (268 a mino acids) and 17.5 ku proteins (159 amino acids). The complete nucleotide sequence of TMV-B is 99.4% identical to that of TMV-U1. The two virus isol ates share the same sequence of 5', 3' non-coding region and 17.5 K ORF, an d 6, 1 and 3 amino acid changes are found in 126 K protein, 54 K protein an d 30 K protein, respectively. The possible mechanism on the infection of TM V-B in Vicia faba is discussed.