EN
The helper component-proteinase (HC-Pro) encoded by plant viruses representing the genus Potyvirus (family Potyviridae) is involved in several important viral life processes, including aphid transmission, systemic movement and suppression of post-transcriptional gene silencing. Some of the viruses belonging to the family of the genera Ipomovirus, Rymovirus and Tritimovirus have been demonstrated to produce HC-Pro homologues that are likely to be engaged in vector transmission of these viruses alone. In this paper, the current knowledge of the structure, main functions and molecular mechanisms of the HC-Pro proteins encoded by viruses from the family Potyviridae is presented.