Glutamic acid at residue 125 of the prM helix domain interacts with positively charged amino acids in E protein domain II for Japanese encephalitis virus-like-particle production.
Interaction between E and prM proteins in flavivirus-infected cells is a major factor for virus-like particle (VLP) production. The prM helical (prM-H) domain is topologically close to and may interact with domain II of the E protein (EDII). In this study, we investigated prM-H domain amino acid residues facing Japanese encephalitis virus EDII using site-directed mutagenesis to determine their roles in prM-E interaction and VLP production. Our results indicate that negatively charged prM-E125 residue at the prM-H domain affected VLP production via one or more interactions with positively charged E-K93 and E-H246 residues at EDII. Exchanges of oppositely charged residue side chains at prM-E125/E-K93 and prM-E125/E-H246 are recoverable for VLP production. The prM-E125 and E-H246 residues are conserved and that the positive charge of the E-K93 residue is preserved in different flavivirus groups. These findings suggest that the electrostatic attractions of prM-E125, E-K93, and E-H246 residues are important to flavivirus VLP production and that inhibiting these interactions is a potential strategy for blocking flavivirus infections.


OBJECTIVE
Molecular interaction between E and prM proteins of Japanese encephalitis virus is a major driving force for virus-like particle (VLP) production. The current high-resolution structures available for prM-E complexes do not include the membrane proximal stem region of prM. The prM stem region contains an N-terminal loop and a helix domain (prM-H). Since the prM-H domain is topologically close to domain II of the E protein (EDII), this study was to determine molecular interactions between the prM-H domain and EDII. We found that the molecular interactions between prM-E125 residue and positively charged E-K93 and E-H246 residues at EDII are critical for VLP production. More importantly, the prM-E125 and E-H246 residues are conserved and the positive charge of the E-K93 residue is preserved in different flavivirus groups. Our findings help refine the structure and molecular interactions on the flavivirus surface and reveal a potential strategy for blocking flavivirus infections by inhibiting these electrostatic interactions.
Institute of Biotechnology, National Tsing Hua University, Hsinchu, Taiwan.
Jia-Guan
JG
Peng
Institute of Biotechnology, National Tsing Hua University, Hsinchu, Taiwan Department of Medical Science, National Tsing Hua University, Hsinchu, Taiwan scwu@mx.nthu.edu.tw.
Suh-Chin
SC
Wu
D000596:Amino Acids / Q000378:metabolism*; D000818:Animals; D002460:Cell Line; D004252:DNA Mutational Analysis; D004664:Encephalitis Virus, Japanese / Q000737:chemistry / Q000502:physiology*; D006801:Humans; D008562:Membrane Glycoproteins / Q000235:genetics / Q000378:metabolism*; D016297:Mutagenesis, Site-Directed; D050505:Mutant Proteins / Q000235:genetics / Q000378:metabolism; D054730:Protein Interaction Domains and Motifs; D025941:Protein Interaction Mapping; D014759:Viral Envelope Proteins / Q000235:genetics / Q000378:metabolism*; D022701:Virosomes / Q000737:chemistry; D019065:Virus Assembly
D000596:Amino Acids; D008562:Membrane Glycoproteins; D050505:Mutant Proteins; D014759:Viral Envelope Proteins; D022701:Virosomes; C080628:glycoprotein E, Japanese encephalitis virus; C074932:prM protein, Flavivirus