ORF 5 of grapevine virus A encodes a nucleic acid-binding protein and affects pathogenesis.

A previous functional analysis of the genome of grapevine virus A (GVA) was not conclusive as to the role of open reading frame 5 (ORF 5). This ORF encodes a 10-kDa protein (p10) carrying two distinct domains: a basic, arginine-rich domain and a zinc-finger domain. P10 was cloned and expressed in Escherichia coli, and was shown by northwestern assays to interact with nucleic acids.