Complete sequence of an infectious full-length cDNA clone of citrus tatter leaf capillovirus: comparative sequence analysis of capillovirus genomes

1 Laboratory of Bioresource Technology, Division of Agriculture and Agricultural Life Sciences, Graduate School, The University of Tokyo, Midori-cho, Tanashi, Tokyo 188, Japan 2 Department of Microbiology, University of Pennsylvania, Philadelphia, Pennsylvania, USA 3 Plant Biotechnology Laboratory, Institute of Fundamental Research, Suntory Research Center, Mishima-gun, Osaka 618, Japan and 4 Laboratory of Plant Pathology, Koibuchi Gakuen, Koibuchi, Uchihara-machi, Higashiibaragi-gun, Ibaragi 319-03, Japan The complete nucleotide sequence of citrus tatter leaf capillovirus (CTLV lily strain) was determined. It is 6496 nucleotides long, excluding the 3'-terminal poly(A) tract, and contains two putative overlapping open reading frames (ORFs). ORF1 (positions 37-6354) encodes a potential polyprotein of molecular mass 242 kDa. ORF2 (positions 4788-5750) codes for a 36 kDa protein. The 242 kDa polypeptide contains several non-structural protein domains (i.e. methyltransferase, NTP-binding helicase, papain-like proteinase and polymerase) and, at its C terminus, the putative coat protein. The N-terminal region of the 36 kDa protein displays sequence similarity to the cell-to-cell movement proteins of the ‘30 K superfamily’. Such a genome structure is conserved between CTLV and apple stem grooving capillovirus. Capped transcripts from a plasmid containing the complete sequence of CTLV, with a T7 RNA promoter, successfully infected Chenopodium quinoa plants and caused symptoms characteristic of CTLV. Uncapped transcripts were non-infectious. * Author for correspondence. Fax +81 424 64 4391. e-mail snamba@ims.u-tokyo.ac.jp Present address: Plant Biotechnology Laboratory, Institute of Fundamental Research, Suntory Research Center, 1-1-1 Wakayamadai Shimamoto-cho, Mishima-gun, Osaka 618, Japan. Received 10 February 1995; accepted 3 May 1995.