Table 1.

Models obtained by regression analysis to single-point mutants of GpA

Model	Data (n)	Model coefficients						R2	Accuracy
		k (σ)	clsh (σ)	dsrot (σ)	vdw (σ)	ges (σ)	vol (σ)		Rgrp2	calc (Pcalc)	Mean (Pmean)	Mode (Pmode)
I	All	2.26	−1.29	+0.28	+0.10	−0.36	−0.06	0.535	0.496	79	45	59
	(165)	(0.08)	(0.13)	(0.11)	(0.02)	(0.04)	(0.02)			(2⋅10−10)	(0.28)	(1⋅10−3)
II	Polar	1.67	−0.83	–*	–*	−0.33	–*	0.312	0.240	24	14	24
	(60)	(0.19)	(0.19)			(0.09)				(7⋅10−3)	(0.67)	(7⋅10−3)
III	Apolar	2.72	−1.62	+0.54	+0.19	–*	–*	0.743	0.760	75	26	56
	(105)	(0.06)	(0.11)	(0.08)	(0.02)					(2⋅10−23)	(0.56)	(2⋅10−9)
IV	All	1.91	–†	–†	–†	−0.34	−0.11	0.209	0.265	54	45	59
	(165)	(0.08)				(0.06)	(0.03)			(0.02)	(0.28)	(1⋅10−3)

The sizes (n) of the “polar” (Gly, Ser, Thr, Tyr) and “apolar” (Ala, Cys, Val, Ile, Leu, Met, Phe, Trp) subsets are given in parentheses. Standard deviations (σ) are given in parentheses below the coefficients. R² is the square of the regression coefficient. Accuracy: number of mutant phenotypes correctly predicted by the regression model (calc), the mean of the data (mean), or the mode of the data (mode). The probability of equaling or exceeding these scores by chance, as calculated using Eq. 2, is given in parentheses below the accuracy scores. 

^*Excluded from regression: 2σ confidence limits for the coefficient overlap zero. 

^†Excluded from regression to test a hypothesis.