Diversification of a single ancestral gene into a successful toxin superfamily in highly venomous Australian funnel-web spiders

Table 1 Nucleotide and complementary protein analyses for ω toxins

Site^a		CodeML		Tree SAAP		Accessible surface area^f
Codon	Amino Acid	M2a^b	M8^c	Property^d	Magnitude^e	Accessible surface area^f
21	E	0.99 ± 0.38	0.87 ± 0.42	-	-	-
21	E	(0.201)	(0.257)	-	-	-
40	V	1.41 ± 0.49	1.47 ± 0.37	M_W, M_V, V⁰, μ	8, 8, 8, 8	42.0
40	V	(0.589)	(0.842)	M_W, M_V, V⁰, μ	8, 8, 8, 8	Partially exposed
44	S	1.25 ± 0.37	1.28 ± 0.41	M^W, M_V, V⁰, μ	8, 8, 8, 8	82.1
44	S	(0.420)	(0.647)	M^W, M_V, V⁰, μ	8, 8, 8, 8	Exposed
53	H	1.62 ± 0.63	1.55 ± 0.36	-	-	0.0
53	H	(0.749)	(0.929)	-	-	Buried
57	G	1.39 ± 0.48	1.45 ± 0.38	-	-	57.3
57	G	(0.570)	(0.825)	-	-	Exposed
60	T	0.80 ± 0.44	0.71 ± 0.41	-	-	49.7
60	T	(0.122)	(0.154)	-	-	Exposed
64	N	0.53 ± 0.40	0.51 ± 0.30	-	-	100.0
64	N	(0.031)	(0.036)	-	-	Exposed
69	T	1.34 ± 0.45	1.38 ± 0.40	-	-	59.8
69	T	(0.507)	(0.751)	-	-	Exposed
72	R	1.10 ± 0.33	1.01 ± 0.42	-	-	0.0
72	R	(0.26)	(0.374)	-	-	Buried

^aSites detected as positively selected using the integrative approach.
^bM2a Bayes empirical Bayes (BEB) posterior probability and post-mean ω indicated in parentheses.
^cM8 Bayes empirical Bayes (BEB) posterior probability and post-mean ω indicated in parentheses.
^dAmino acid property under selection (M_W: molecular weight; M_V: molecular volume; V⁰: partial specific volume; μ: Refractive index).
^eMagnitude if selection on the amino acid property.
^fAccessible surface area of 10–20% corresponds to buried residues, 40–50% indicates partially exposed amino acid residues, and ≥50% indicates solvent exposed residues.

ISSN: 1471-2164