Proc Natl Acad Sci U S A. 1983 Jan;80(2):422-4. doi: 10.1073/pnas.80.2.422.
Proceedings of the National Academy of Sciences of the United States of America
H Fraenkel-Conrat
PMID: 16593271 PMCID: PMC393389 DOI: 10.1073/pnas.80.2.422
The existence of RNA-dependent RNA polymerases (EC 2.7.7.48) in plants has been definitely proven by their isolation in pure form from cucumber and tobacco in our laboratory and from cowpea at Wageningen. These enzymes are single-chain proteins of 100-130 kilodaltons. They show clear physical and biochemical differences characteristic for a given plant species, even when their amounts in the plants were greatly increased prior to isolation by infection with the same virus. The role of these enzymes in plant physiology remains unknown.