title: Autographa californica multiple nucleopolyhedrovirus GP64 protein: Analysis of domain I and V amino acid interactions and membrane fusion activity.
abstract: The Autographa californica multiple nucleopolyhedrovirus GP64 is a class III viral fusion protein. Although the post-fusion structure of GP64 has been solved, its pre-fusion structure and the detailed mechanism of conformational change are unknown. In GP64, domain V is predicted to interact with two domain I segments that flank fusion loop 2. To evaluate the significance of the amino acids involved in these interactions, we examined 24 amino acid positions that represent interacting and conserved residues within domains I and V. In several cases, substitution of a single amino acid involved in a predicted interaction disrupted membrane fusion activity, but no single amino acid pair appears to be absolutely required. We identified 4 critical residues in domain V (G438, W439, T452, and T456) that are important for membrane fusion, and two residues (G438 and W439) that appear to be important for formation or stability of the pre-fusion conformation of GP64.
authors.affiliation: State Key Laboratory of Crop Stress Biology for Arid Areas, Key Laboratory of Northwest Loess Plateau Crop Pest Management of Ministry of Agriculture, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi 712100, China.
authors.forename: Qianlong
authors.initials: Q
authors.lastname: Yu
authors.affiliation: Boyce Thompson Institute, Cornell University, Ithaca, NY 14853, United State.
authors.forename: Gary W
authors.initials: GW
authors.lastname: Blissard
authors.affiliation: State Key Laboratory of Crop Stress Biology for Arid Areas, Key Laboratory of Northwest Loess Plateau Crop Pest Management of Ministry of Agriculture, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi 712100, China.
authors.forename: Tong-Xian
authors.initials: TX
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Crop Stress Biology for Arid Areas, Key Laboratory of Northwest Loess Plateau Crop Pest Management of Ministry of Agriculture, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi 712100, China. Electronic address: zhaofeili73@outlook.com.
authors.forename: Zhaofei
authors.initials: Z
authors.lastname: Li
mesh_terms: D019943:Amino Acid Substitution; D000596:Amino Acids / Q000235:genetics / Q000378:metabolism*; D004252:DNA Mutational Analysis; D017924:Nucleopolyhedroviruses / Q000235:genetics / Q000502:physiology*; D011487:Protein Conformation; D055550:Protein Stability; D017434:Protein Structure, Tertiary; D014760:Viral Fusion Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D053586:Virus Internalization
chemical_list: D000596:Amino Acids; D014760:Viral Fusion Proteins
keywords: AcMNPV; Class III viral fusion protein; Domain V; GP64; Pre-fusion conformation