title: The autocatalytic protease p29 encoded by a hypovirulence-associated virus of the chestnut blight fungus resembles the potyvirus-encoded protease HC-Pro.
abstract: Gene expression by a viral-like double-stranded RNA genetic element associated with reduced virulence (hypovirulence) of the chestnut blight fungus was recently shown to involve an autoproteolytic event which resulted in the release of an encoded protease, designated p29, from a polyprotein during translation. Mutational analysis of p29, described in this report, revealed that residues Cys-162 and His-215 are essential for autocatalytic cleavage. The results were also consistent with previous predictions that cleavage occurs between Gly-248 and Gly-249. Interestingly, p29 bears a striking resemblance to the potyvirus-encoded protease HC-Pro. Both proteases autocatalytically cleave at glycine dipeptides. In addition, there is a significant degree of similarity in the amino acid sequences flanking the essential Cys and His residues of the two proteases and in the spacing of these residues from their respective cleavage sites.
authors.affiliation: Department of Molecular Oncology and Virology, Roche Institute of Molecular Biology, Nutley, New Jersey 07110.
authors.forename: G H
authors.initials: GH
authors.lastname: Choi
authors.forename: D M
authors.initials: DM
authors.lastname: Pawlyk
authors.forename: D L
authors.initials: DL
authors.lastname: Nuss
mesh_terms: D000595:Amino Acid Sequence; D001203:Ascomycota / Q000201:enzymology / Q000235:genetics* / Q000472:pathogenicity; D003546:Cysteine Endopeptidases / Q000302:isolation & purification / Q000378:metabolism*; D010450:Endopeptidases / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D016366:Open Reading Frames; D010942:Plant Viruses / Q000201:enzymology* / Q000235:genetics; D014176:Protein Biosynthesis; D012328:RNA Viruses / Q000201:enzymology* / Q000235:genetics; D012330:RNA, Double-Stranded; D012367:RNA, Viral; D012689:Sequence Homology, Nucleic Acid; D014774:Virulence / Q000235:genetics
chemical_list: D012330:RNA, Double-Stranded; D012367:RNA, Viral; D010450:Endopeptidases; D003546:Cysteine Endopeptidases; C069855:protease p29