... attach-ment protein for host cell receptors (sialylated glycocon-jugates), enhances the fusogenic activity of the viral F protein to allow viral entry into the cell, and its sialidaseactivity hydrolyzes ... virus genotype. Vaccine 20 01, 19 :17 27 -17 31. 15 . Jin L, Beard S, Brown DW: Genetic heterogeneity of mumps virus in the United Kingdom: identification of two new genotypes. J Infect Dis 19 99, 18 0:829-833. 16 . ... indicates the nucleus. 40×Herrera et al. Virology Journal 2 010 , 7 :19 5http://www.virologyj.com/content/7 /1/ 195Page 4 of 11 defined on the basis of the nucleotide sequence of the MuV SH gene [6 ,10 , 21] ....