Table 3 Linear regression equations calculated plotting the value of GC content in each protein family, i.e., SIRTs, myoglobins and alpha-crystallins (a and b chains) on the y axis and the various organisms in phylogenetic order on X axis

SIRT1s

y = 0.898x + 36.77

y = 0.310x + 37.89

y = 1.915x + 34.01

y = 0.520x + 37.62

SIRT2s

y = 0.832x + 38.50

y = 0.888x + 37.60

y = 0.957x + 38.64

y = 1.336x + 30.96

SIRT3s

y = 0.529x + 54.32

y = 0.879x + 49.96

y = 1.316x + 49.76

y = 1.278x + 43.10

SIRT4s

y = 0.933x + 43.09

y = 1.016x + 42.07

y = 0.402x + 48.88

y = 0.389x - 0.317

SIRT5s

y = 0.926x + 44.12

y = 0.947x + 44.11

y = 0.830x + 44.55

y = −0.435x + 6.341

SIRT6s

y = 2.221x + 36.85

y = 1.766x + 40.43

y = 1.912x + 44.92

y = 3.389x + 30.43

SIRT7s

y = 3.841x + 30.92

y = 2.053x + 42.16

y = 2.939x + 45.57

y = 2.177x + 42.60

Myoglobins

y = 0,247x + 47,89

Alpha Crystallins

chain A

y = 1.223x + 47.12

chain B

y = 0.290x + 52.71