Table 2.
Examples of low and high MPD codon scores associated with invariant arginine (R) amino acid (AA) residues are tabulated
| Codon | AA | Obsa | Expb |
|---|---|---|---|
| (a) PB1 ORF, position 755 | |||
| CGU | R | 0 | 6.0 |
| CGC | R | 0 | 18.7 |
| CGA | R | 0 | 22.7 |
| CGG | R | 351 | 36.9 |
| AGA | R | 0 | 170.3 |
| AGG | R | 0 | 96.4 |
| MPDc: | 0 | 0.93 | |
| Normd: | 0 | ||
| (b) PB2 ORF, position 427 | |||
| CGU | R | 1 | 7.8 |
| CGC | R | 2 | 23.1 |
| CGA | R | 192 | 33.5 |
| CGG | R | 81 | 26.7 |
| AGA | R | 87 | 185.4 |
| AGG | R | 6 | 92.4 |
| MPD | 0.75 | 0.91 | |
| Norm: | 0.82 | ||
aObserved frequency of codons at specified position.
bHypothetical predicted occurence of codons based on overall codon usage data for the segment.
cCalculated mean pairwise difference (MPD) of the codon distribution.
dNorm = observed MPD/expected MPD.