Spectrum of disease-causing mutations in protein secondary structures

BMC Structural Biology

Table 3 Spectrum of mutations appearing in α-helix, β-strand, turn and bend structures, expected values are calculated from mutated and mutant amino acid composition in the studied proteins^a

Amino acid	Original residues	Expected residues	χ²	P value	Mutant residues	Expected residues	χ²	P value
A	148	136	1.07	3.00E-01	58	67	1.15	2.84E-01
C	54	64	1.43	2.32E-01	117	107	0.94	3.32E-01
D	81	79	0.06	8.06E-01	112	125	1.28	2.57E-01
E	96	91	0.29	5.91E-01	71	68	0.18	6.75E-01
F	53	53	0.00	9.91E-01	77	72	0.29	5.87E-01
G	220	198	2.48	1.15E-01	95	85	1.12	2.91E-01
H	63	70	0.69	4.05E-01	91	87	0.20	6.57E-01
I	83	80	0.14	7.05E-01	55	64	1.36	2.44E-01
K	43	45	0.09	7.61E-01	92	88	0.21	6.43E-01
L	188	186	0.03	8.70E-01	96	91	0.29	5.91E-01
M	65	63	0.08	7.74E-01	48	78	11.54***	6.79E-04
N	60	72	2.12	1.46E-01	61	60	0.04	8.47E-01
P	68	76	0.76	3.82E-01	170	156	1.25	2.63E-01
Q	45	50	0.47	4.91E-01	89	92	0.13	7.17E-01
R	299	280	1.31	2.53E-01	196	179	1.71	1.91E-01
S	78	101	5.05*	2.46E-02	144	140	0.12	7.31E-01
T	62	68	0.46	4.99E-01	119	109	0.85	3.57E-01
V	122	118	0.12	7.28E-01	138	149	0.78	3.77E-01
W	44	44	0.00	9.72E-01	56	62	0.57	4.51E-01
Y	67	68	0.00	9.46E-01	54	61	0.83	3.62E-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.

ISSN: 1472-6807