Table 9

Spectrum of mutations in α-helices in amino acid groupsa

Amino acid group

Original residues

Expected residues

χ2

P value

Mutant residues

Expected residues

χ2

P value


Hydrophobic

355

348

0.13

7.19E-01

320

322

0.01

9.13E-01

Positively charged

95

140

14.36***

1.51E-04

85

71

2.75

9.71E-02

Negatively charged

196

147

16.56***

4.71E-05

166

152

1.39

2.39E-01

Conformational

77

54

9.96**

1.60E-03

136

111

5.50*

1.90E-02

Polar

86

118

8.70**

3.17E-03

137

159

2.94

8.62E-02

A+T

119

121

0.04

8.34E-01

84

114

7.73**

5.44E-03


Sum

928

928

928

928


aχ2-numbers in italics indicate underrepresentation and numbers in bold overrepresentation compared to random distribution based on amino acid frequencies. The results of the χ2 are shown with significance level: * P < 0.05; ** P < 0.01; *** P < 0.001.

Khan and Vihinen BMC Structural Biology 2007 7:56   doi:10.1186/1472-6807-7-56

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