Table 1 Degree distribution of PINs with respect to the centre

1

2

3

4

5

6

7

8

9

Homo sapiens

9448

181706

13

MAPK14

374

4610

3464

578

104

14

2

1

1

Nodes

86

32

52

2

2

1

1

2

1

Average degree

3

1

1

1

1

1

1

2

1

Lowest degree

531

430

393

14

6

2

2

2

1

Highest degree

0

173

653

307

56

12

1

0

1

No of quills

HSN

6291

62737

11

MAPK1

431

3527

1929

206

38

4

Nodes

67

24

7

2

2

3

Average degree

1

1

1

1

1

1

Lowest degree

451

362

89

11

9

5

Highest degree

4

404

757

133

20

2

No of quills

Saccharomyces cerevisiae

5033

22417

10

SSC1

175

1639

2517

565

69

9

Nodes

34

14

4

1

1

1

Average degree

1

1

1

1

1

1

Lowest degree

209

282

109

11

4

1

Highest degree

1

92

609

327

57

9

No of quills

Arabidopsis thaliana

2953

6783

16

AT1G78300

134

216

799

825

443

130

20

5

4

Nodes

3

11

6

3

2

1

1

3

2

Average degree

1

1

1

1

1

1

1

1

1

Lowest degree

62

117

79

43

26

12

4

6

3

Highest degree

81

60

180

355

234

80

10

1

1

No of quills

Escherichia coli

2949

12689

12

rpsB

151

1089

976

260

38

6

Nodes

37

12

3

1

1

1

Average degree

1

1

1

1

1

1

Lowest degree

178

127

56

6

3

2

Highest degree

1

213

349

166

30

5

No of quills