FIG 1.

Location of amino acid 36 in JEV M protein. (A) Structure of the E-M mature heterodimer. The structure was derived from the cryoelectron microscopy structure of a mature dengue virus serotype 2 (DV2) (Protein Data Bank [PDB] accession no. 3J27), while the DV2 E protein was replaced with that of Japanese encephalitis virus (JEV) (PDB accession no. 3P54) using PyMOL. Domains I, II, and III of the E protein are colored in red, yellow, and blue, respectively, while E perimembrane and transmembrane helices are colored in gray. The M protein is colored in magenta, each portion being annotated (N-terminal loop [N-ter], perimembrane helix [H], transmembrane helices [TM]), and the isoleucine located at position 36 is colored in green. (B) The sequences for JEV (GenBank accession [GBA] no. AHK05344), West Nile virus (WNV; GBA no. YP_001527877), DV serotypes 1, 2, 3, and 4 (GBA no. U88535, M29095, AY858048, and AY776330, respectively), and yellow fever virus (YFV wild-type [wt] strain, GBA no. AHB63685; and YFV vaccine [vac] strain, GBA no. AGO04419) M perimembrane helices were aligned using ClustalW2. Conserved amino acids (indicated by asterisks) and semiconserved amino acids (indicated by colons and periods) are indicated below the alignment. The perimembrane helix is underlined, and amino acid residue 36, mutagenized in this study, is highlighted in gray.