Helper-component proteinase

Helper-component proteinase (EC 3.4.22.45, HC-Pro) is an enzyme.^[1][2] This enzyme catalyses the following chemical reaction

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

Helper-component proteinase
Identifiers
EC no.	3.4.22.45
CAS no.	124566-20-7
Databases
IntEnz	IntEnz view
BRENDA	BRENDA entry
ExPASy	NiceZyme view
KEGG	KEGG entry
MetaCyc	metabolic pathway
PRIAM	profile
PDB structures	RCSB PDB PDBe PDBsum
Search PMC articles PubMed articles NCBI proteins

This enzyme is present in plant RNA viruses of the Potyviridae family. HC-Pro is encoded by all potyviruses, but is absent in some members of the Ipomovirus genus.^[3] HC-Pro is involved in virus transmission, virus polyprotein processing, and suppression of RNA silencing, an antiviral mechanism of plants.^[4]