title: Genetic diversity of the E protein of dengue type 3 virus.
abstract: BACKGROUND
  Dengue is the most important arbovirus disease in tropical and subtropical countries. The viral envelope (E) protein is responsible for cell receptor binding and is the main target of neutralizing antibodies. The aim of this study was to analyze the diversity of the E protein gene of DENV-3. E protein gene sequences of 20 new viruses isolated in Ribeirao Preto, Brazil, and 427 sequences retrieved from GenBank were aligned for diversity and phylogenetic analysis.
  
  
  RESULTS
  Comparison of the E protein gene sequences revealed the presence of 47 variable sites distributed in the protein; most of those amino acids changes are located on the viral surface. The phylogenetic analysis showed the distribution of DENV-3 in four genotypes. Genotypes I, II and III revealed internal groups that we have called lineages and sub-lineages. All amino acids that characterize a group (genotype, lineage, or sub-lineage) are located in the 47 variable sites of the E protein.
  
  
  CONCLUSIONS
  Our results provide information about the most frequent amino acid changes and diversity of the E protein of DENV-3.
authors.affiliation: Virology Research Center, School of Medicine of Ribeirão Preto/USP, Ribeirão Preto - SP, Brazil. alberilla@yahoo.com.ar
authors.forename: Alberto A
authors.initials: AA
authors.lastname: Amarilla
authors.forename: Flavia T
authors.initials: FT
authors.lastname: de Almeida
authors.forename: Daniel M
authors.initials: DM
authors.lastname: Jorge
authors.forename: Helda L
authors.initials: HL
authors.lastname: Alfonso
authors.forename: Luiza A
authors.initials: LA
authors.lastname: de Castro-Jorge
authors.forename: Nadia A
authors.initials: NA
authors.lastname: Nogueira
authors.forename: Luiz T
authors.initials: LT
authors.lastname: Figueiredo
authors.forename: Victor H
authors.initials: VH
authors.lastname: Aquino
mesh_terms: D019943:Amino Acid Substitution / Q000235:genetics; D001938:Brazil; D016000:Cluster Analysis; D003715:Dengue / Q000821:virology*; D003716:Dengue Virus / Q000235:genetics* / Q000302:isolation & purification; D005838:Genotype; D006801:Humans; D008969:Molecular Sequence Data; D010802:Phylogeny; D011110:Polymorphism, Genetic; D017422:Sequence Analysis, DNA; D017385:Sequence Homology; D014759:Viral Envelope Proteins / Q000235:genetics*
chemical_list: C084188:E protein, Dengue virus type 3; D014759:Viral Envelope Proteins