Foot-and-mouth Disease Virus Proteinases and Polyprotein Processing
Fiona Tulloch, Garry A. Luke and Martin D. Ryan
from: Foot-and-Mouth Disease Virus: Current Research and Emerging Trends (Edited by: Francisco Sobrino and Esteban Domingo). Caister Academic Press, U.K. (2017) Pages: 43-60.
Foot-and-mouth disease virus encodes all of its proteins in a single, long, open reading frame which encodes a polyprotein. The full-length translation product (~ 2,330 amino acids) is not observed within infected cells, however, due to 'processing' of this polyprotein. The polyprotein undergoes extremely rapid co-translational, intramolecular, or 'primary', cleavages at three sites by the activities of the virus-encoded proteinases L and 3C, and a short oligopeptide sequence (2A) which mediates a ribosome 'skipping' activity - a translational 'recoding' event. The primary cleavage products then undergo 'secondary' proteolytic processing by a combination of inter- and intramolecular cleavages to produce the mature processing products. The L and 3C proteinases serve not only to cleave the virus polyprotein, but also to degrade specific host-cell proteins thereby greatly enhancing virus replication and suppressing the innate immune response to infection read more ...