Table 4

Spectrum of mutations appearing in α-helix, β-strand, turn and bend structures. Expected values are calculated from amino acid composition in secondary structural elementsa

Amino acid

Original residues

Expected residues

χ2

P value

Mutant residues

Expected residues

χ2

P value


A

148

139

0,53

4.66E-01

58

119

31.05***

2.51E-08

C

54

32

15,50***

6.82E-05

117

69

32.93***

9.58E-09

D

81

96

2,34

1.26E-01

112

79

13.64***

2.21E-04

E

96

147

17,60***

2.71E-05

71

69

0.04

8.33E-01

F

53

87

13,51***

2.36E-04

77

79

0.06

8.10E-01

G

220

136

52,47***

4.48E-13

95

114

3.10

7.85E-02

H

63

48

5,06*

2.47E-02

91

79

1.78

1.83E-01

I

83

110

6,51**

1.07E-02

55

104

23.00***

1.62E-06

K

43

113

43,42***

4.37E-11

92

69

7.47**

6.26E-03

L

188

205

1,34

2.46E-01

96

163

27.69***

1.42E-07

M

65

49

5,02*

2.51E-02

48

45

0.27

6.02E-01

N

60

69

1,10

2.93E-01

61

79

4.16*

4.14E-02

P

68

67

0,02

8.98E-01

170

119

22.16***

2.51E-06

Q

45

82

16,87***

3.98E-05

89

69

5.63*

1.76E-02

R

299

119

272,51***

3.43E-61

196

168

4.60*

3.19E-02

S

78

104

6,60**

1.01E-02

144

183

8.32**

3.92E-03

T

62

92

10,03**

1.53E-03

119

119

0.00

9.79E-01

V

122

144

3,33

7.01E-02

138

119

3.13

7.67E-02

W

44

30

6,27**

1.23E-02

56

35

13.20***

2.81E-04

Y

67

70

0,15

6.95E-01

54

59

0.48

4.87E-01


Sum

1939

1939

1939

1939


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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