Mutation in the VP-1 gene is responsible for the extended host range of a monkey B-lymphotropic papovavirus mutant capable of growing in T-lymphoblastoid cells.

Monkey B-lymphotropic papovavirus (LPV) replicates only in B-lymphoblastoid cells, whereas the LPV mutant 76 (LPV-76) can grow in either B- or T-lymphoblastoid cells. The nucleotide sequence of the wild-type LPV PstI B segment was compared with that of LPV-76 PstI-B, within which the mutation responsible for the extended host range had been located. The VP-1 coding region of LPV-76 was found to have mutations, single-base substitutions causing three amino acid substitutions.