Open AccessGene I, a potential cell-to-cell movement locus of cauliflower mosaic virus, encodes an RNA-binding protein.
Author(s) -
Vitaly Citovsky,
David A. Knorr,
Patricia Zambryski
Publication year - 1991
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.88.6.2476
Subject(s) - plasmodesma , movement protein , biology , rna , cauliflower mosaic virus , gene , dna , tobacco mosaic virus , transcription (linguistics) , microbiology and biotechnology , genetics , cell , virus , genetically modified crops , coat protein , transgene , linguistics , philosophy
Cauliflower mosaic virus (CaMV) is a double-stranded DNA (dsDNA) pararetrovirus capable of cell-to-cell movement presumably through intercellular connections, the plasmodesmata, of the infected plant. This movement is likely mediated by a specific viral protein encoded by the gene I locus. Here we report that the purified gene I protein binds RNA and single-stranded DNA (ssDNA) but not dsDNA regardless of nucleotide sequence specificity. The binding is highly cooperative, and the affinity of the gene I protein for RNA is 10-fold higher than for ssDNA. CaMV replicates by reverse transcription of a 358 RNA that is homologous to the entire genome. We propose that the 35S RNA may be involved in cell-to-cell movement of CaMV as an intermediate that is transported through plasmodesmata as an RNA-gene I protein complex.