title: Novel ATPase activity of the polyprotein intermediate, Viral Protein genome-linked-Nuclear Inclusion-a protease, of Pepper vein banding potyvirus.
abstract: Potyviruses temporally regulate their protein function by polyprotein processing. Previous studies have shown that VPg (Viral Protein genome-linked) of Pepper vein banding virus interacts with the NIa-Pro (Nuclear Inclusion-a protease) domain, and modulates the kinetics of the protease. In the present study, we report for the first time that VPg harbors the Walker motifs A and B, and the presence of NIa-Pro, especially in cis (cleavage site (E191A) VPg-Pro mutant), is essential for manifestation of the ATPase activity. Mutation of Lys47 (Walker motif A) and Asp88:Glu89 (Walker motif B) to alanine in E191A VPg-Pro lead to reduced ATPase activity, confirming that this activity was inherent to VPg. We propose that potyviral VPg, established as an intrinsically disordered domain, undergoes plausible structural alterations upon interaction with globular NIa-Pro which induces the ATPase activity.
authors.affiliation: Department of Biochemistry, Indian Institute of Science, Bangalore 560012, India.
authors.forename: Chhavi
authors.initials: C
authors.lastname: Mathur
authors.forename: Handanahal S
authors.initials: HS
authors.lastname: Savithri
mesh_terms: D000251:Adenosine Triphosphatases / Q000737:chemistry*; D000595:Amino Acid Sequence; D002212:Capsicum / Q000821:virology*; D004252:DNA Mutational Analysis; D008969:Molecular Sequence Data; D017800:Potyvirus / Q000201:enzymology* / Q000235:genetics; D014764:Viral Proteins / Q000737:chemistry* / Q000235:genetics
chemical_list: C520979:VPg protein, poliovirus; D014764:Viral Proteins; D000251:Adenosine Triphosphatases