The 12 kDa protein of potato virus M displays properties of a nucleic acid‐binding regulatory protein

The 3' terminal 1.4 kb segment of potato virus M (PVM) genomic RNA was cloned and sequenced. This part of the viral genome encodes the capsid protein CP as well as a 12 kDa protein of as yet unknown function. Both proteins were expressed in bacteria and their nucleic acid‐binding properties studied. The 12 kDa protein (prl2), but not the capsid protein bound single‐ and double‐stranded nucleic acids. This property of prl2 in conjunction with a zinc finger motif located adjacent to a basic region of the 12 kDa protein suggests that it may act as a regulatory factor during virus replication.