Table 5

Lipid contact statistics in TM and non-TM proteins with (a) head group and (b) tail group atoms

Transmembrane (TM) proteins

Non-transmembrane (non-TM) proteins



Obsa

Expa

Counts

Signed chi-square

P-value

Obsa

Expa

Counts

Signed chi-square

P-value


(a) Head group

TRP†, ‡

22

9.12

290

18.19

2.00E-05

3

2.23

84

0.27

6.06E-01

PHE†, ‡

35

22.65

720

6.74

9.43E-03

13

9.06

341

1.72

1.90E-01

TYR†, ‡

28

12.90

410

17.69

2.60E-05

21

7.25

273

26.08

3.27E-07

LEU

28

37.40

1189

-2.36

1.24E-01

20

21.85

823

-0.16

6.92E-01

ILE

11

23.18

737

-6.40

1.14E-02

9

11.58

436

-0.57

4.49E-01

CYS

2

4.25

135

-1.19

2.76E-01

2

4.51

170

-1.40

2.37E-01

MET

11

11.51

366

-0.02

8.80E-01

1

4.22

159

-2.46

1.17E-01

GLY

15

28.06

892

-6.07

1.37E-02

15

13.54

510

0.16

6.92E-01

VAL

16

26.70

849

-4.29

3.83E-02

14

15.11

569

-0.08

7.75E-01

SER

14

20.57

654

-2.10

1.47E-01

13

15.61

588

-0.44

5.08E-01

THR

16

19.53

621

-0.64

4.24E-01

5

10.62

400

-2.98

8.45E-02

ALA

16

29.85

949

-6.42

1.13E-02

12

17.55

661

-1.76

1.85E-01

HIS†, ‡

16

8.05

256

7.85

5.09E-03

7

5.47

206

0.43

5.13E-01

ASN†, ‡

22

11.45

364

9.73

1.82E-03

11

9.00

339

0.44

5.06E-01

PRO

9

15.98

508

-3.05

8.09E-02

6

10.36

390

-1.83

1.76E-01

GLN†, ‡

14

8.30

264

3.91

4.80E-02

12

9.77

368

0.51

4.76E-01

ARG†, ‡

32

13.24

421

26.58

2.53E-07

20

10.41

392

8.84

2.95E-03

LYS†, ‡

20

12.20

388

4.98

2.56E-02

20

13.01

490

3.75

5.27E-02

ASP

6

11.73

373

-2.80

9.43E-02

5

11.79

444

-3.91

4.80E-02

GLU

8

14.34

456

-2.80

9.40E-02

7

13.04

491

-2.80

9.45E-02

(b) Tail group

TRP†, ‡

42

12.9

290

65.46

5.93E-16

9

3.07

84

11.48

7.05E-04

PHE†, ‡

63

32.1

720

29.82

4.75E-08

35

12.45

341

40.84

1.66E-10

TYR†, ‡

21

18.3

410

0.41

5.22E-01

20

9.97

273

10.10

1.49E-03

LEU†, ‡

85

53.0

1189

19.37

1.08E-05

68

30.05

823

47.92

4.43E-12

ILE†, ‡

48

32.8

737

7.01

8.12E-03

33

15.92

436

18.33

1.86E-05

CYS

7

6.0

135

0.16

6.88E-01

5

6.21

170

-0.23

6.28E-01

MET†, ‡

24

16.3

366

3.63

5.67E-02

13

5.81

159

8.92

2.83E-03

GLY

17

39.7

892

-13.01

3.10E-04

4

18.62

510

-11.48

7.03E-04

VAL†, ‡

47

37.8

849

2.23

1.36E-01

34

20.78

569

8.42

3.72E-03

SER

26

29.1

654

-0.34

5.61E-01

8

21.47

588

-8.45

3.65E-03

THR

21

27.7

621

-1.61

2.05E-01

7

14.61

400

-3.96

4.66E-02

ALA

39

42.3

949

-0.25

6.14E-01

24

24.14

661

0.00

9.78E-01

HIS

6

11.4

256

-2.56

1.10E-01

3

7.52

206

-2.72

9.92E-02

ASN

7

16.2

364

-5.24

2.21E-02

3

12.38

339

-7.11

7.69E-03

PRO

8

22.6

508

-9.46

2.10E-03

9

14.24

390

-1.93

1.65E-01

GLN

6

11.8

264

-2.82

9.30E-02

2

13.44

368

-9.73

1.81E-03

ARG

5

18.8

421

-10.09

1.49E-03

7

14.31

392

-3.74

5.32E-02

LYS

4

17.3

388

-10.21

1.40E-03

8

17.89

490

-5.47

1.94E-02

ASP

1

16.6

373

-14.68

1.28E-04

2

16.21

444

-12.46

4.16E-04

GLU

6

20.3

456

-10.09

1.49E-03

3

17.93

491

-12.43

4.22E-04


Statistically significant values (p-value <0.05 or 95% significance) are in bold font. The amino acids are sorted in the ascending order of the lipophilicity scale for POPC interface.

†, ‡ The dagger and double-dagger symbols are used to show residues in which observed contacts are more than expected for TM and non-TM proteins, respectively.

a Obs and Exp stand for observed and expected number of counts, respectively.

Morita et al. BMC Biophysics 2011 4:21   doi:10.1186/2046-1682-4-21

Open Data