TABLE 4.

Recovery of rHPIV1 bearing codon substitution mutations at amino acid position 992 in the L protein

VirusCodonaNo. of nucleotide changes needed to restore wild-type amino acidrHPIV1 mutant recovered
rHPIV1 wild typeTTA, TTG, CTT, CTC, CTA, CTG0+
rHPIV1 L992Fcp45TTT1+
rHPIV1 L992MATG1+
rHPIV1 L992HCAC1+
rHPIV1 L992IATC1+
rHPIV1 L992WTGG1+
rHPIV1 L992RCGG1b
rHPIV1 L992VGTC1+
rHPIV1 L992QCAG1b,c
rHPIV1 L992EGAG1d
rHPIV1 L992PCCG1b
rHPIV1 L992AGCG2+
rHPIV1 L992YTAC2+
rHPIV1 L992CTGC2+
rHPIV1 L992NAAC2+
rHPIV1 L992DGAC2d
rHPIV1 L992TACC2c
rHPIV1 L992GGGG2c
rHPIV1 L992KAAG2+
  • a In the case of wild type, the six possible codons yielding the wild-type amino acid for leucine (L) are shown; for each mutant, the codon chosen for introduction into rHPIV1 is shown. A cDNA bearing an L992S mutation was not constructed.

  • b Mutant was recovered but reverted to wild type during passage at 32°C and was not further studied.

  • c Mutant recombined with wild-type pTML1 and was not further studied.

  • d Virus was recovered from transfection, but titer was low and virus was lost on subsequent passage.