Table 3 |
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|
Comparison of selective pressure by transmembrane domain. |
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|
TM1 |
TM2 |
TM3 |
TM4 |
TM5 |
TM6 |
TM7 |
non-TM |
CDS |
|
|
|
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|
Length (amino acids) |
26 |
21 |
19 |
24 |
25 |
19 |
24 |
110 |
268 |
|
Mean pairwise dN/dSa |
0.330 |
0.276 |
0.457 |
0.574 |
0.437 |
0.513 |
0.282 |
0.304 |
0.325 |
|
TM vs loops p-value (2 -tailed t test)b |
9.9E-04 |
0.81 |
2.1E-12 |
7.6E-21 |
1.2E-18 |
2.5E-10 |
1.00 |
||
|
TM vs CDS p-value (2 -tailed t test)b |
0.45 |
0.025 |
2.1E-08 |
5.9E-16 |
7.9E-12 |
6.0E-07 |
0.0024 |
||
|
Number of positively selected sites (p < 0.1)c |
0 |
0 |
1 |
1 |
0 |
0 |
0 |
2 |
4 |
|
Number of negatively selected sites (p < 0.1)c |
21 |
16 |
12 |
15 |
15 |
14 |
19 |
80 |
192 |
|
|
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|
a The mean ratios of non-synonymous substitutions per non-synonymous site (dN) to synonymous substitutions per synonymous site (dS) were calculated for each transmembrane region, the aggregate of the non-transmembrane regions, as well as the entire OR coding sequence. dN/dS ratios were calculated only for pairwise comparisons in which mutational saturation had not been reached. A constant set of 262 informative pairs was used for all calculations. b Probabilities that the average dN/dS ratio for the particular TM domain is no different than the average for the entire CDS or the non-TM domains, using a two-tailed t test. c Number of sites with probabilities greater than 0.9 (p < 0.1) of being positively or negatively selected for each domain. Ancestral sequences were reconstructed, and at every non-constant site, dN and dS were calculated. If dN < (or >) dS, a p-value derived from a two-tailed binomial distribution was used to assess significance. |
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|
Alioto and Ngai BMC Genomics 2005 6:173 doi:10.1186/1471-2164-6-173 |
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