Neutral evolution of Protein-protein interactions: a computational study using simple models

BMC Structural Biology

Table 1 Mutational robustness as a function of the functional constraint

δ	${〈 n 〉}_{r a n d o m}^{A}$	${〈 n 〉}_{r a n d o m}^{B}$	⟨n⟩_random	${〈 n 〉}_{s s}^{A}$	${〈 n 〉}_{s s}^{B}$	⟨n⟩_ss	Survival #	Survival %
0.00	9.18	8.96	18.14	11.48	11.84	23.32	96,108,582	100
0.01	8.47	8.36	16.84	10.95	11.39	22.34	68,290,887	71
0.02	8.03	7.96	16.00	10.61	11.00	21.61	47,695,260	50
0.03	7.67	7.63	15.31	10.30	10.71	21.01	34,273,488	36
0.04	7.43	7.42	14.85	10.10	10.57	20.66	25,785,086	27
0.06	7.06	7.01	14.07	9.69	9.99	19.68	14,825,259	15
0.08	6.71	6.68	13.39	9.38	9.69	19.07	8,983,407	9.3
0.10	6.45	6.42	12.87	9.08	9.40	18.48	5,522,233	5.8
0.15	5.86	5.78	11.64	8.32	8.53	16.86	1,626,428	1.7
0.20	5.18	5.02	10.20	7.48	7.52	15.01	353,538	0.37
0.25	4.43	4.16	8.60	6.21	6.20	12.41	47,192	0.05

Mutational robustness ⟨n⟩ as a function of the functional constraint (measured by δ). Data are shown for a representative 2D dimer. The two partners each have about ten thousand viable sequences. The mean mutational robustness for randomly chosen sequences is ⟨n⟩_random. The robustness averaged over the steady state is ⟨n⟩_ss. These values correspond to the overall mutational robustness of the AB dimer. The separate contributions of each partner, A and B, are also shown. The number and percentage of viable sequence pairs are shown.

ISSN: 1472-6807