Acting on peptide bonds (peptidases);
Hydrolyses a Gly!Gly bond at its own C-terminus, commonly in the sequence -Tyr-Xaa-Val-Gly!Gly, in the processing of the potyviral polyprotein
Known from many potyviruses. The helper component-proteinase of the tobacco etch virus is a multifunctional protein with several known activities: the N-terminal region is required for aphid transmission and efficient genome amplification, the central region is required for long-distance movement in plants, and the C-terminal domain has cysteine endopeptidase activity. Type example of peptidase family C6.