Table 5.

Rate of occurrences/expected number of simple TM helices in membrane proteins with fixed number of TM helices

No. of TMs	f = 1.282			f = 1.645
	Ratio of complex TMs	Ratio of simple TMs	Expected no. of simple TMs	Ratio of complex TMs	Ratio of simple TMs	Expected no. of simple TMs
1	0.42	0.58	0.58	0.58	0.42	0.42
2	0.60	0.40	0.80	0.75	0.25	0.51
3	0.68	0.32	0.95	0.82	0.18	0.55
4	0.73	0.27	1.07	0.86	0.14	0.57
5	0.74	0.26	1.28	0.86	0.14	0.70
6	0.77	0.23	1.41	0.87	0.13	0.75
7	0.78	0.22	1.54	0.89	0.11	0.78
8	0.77	0.23	1.87	0.88	0.12	0.97
9	0.76	0.24	2.18	0.87	0.13	1.15
10	0.77	0.23	2.33	0.88	0.12	1.16
11	0.79	0.21	2.29	0.90	0.10	1.10
12	0.81	0.19	2.30	0.90	0.10	1.15
13	0.80	0.20	2.56	0.90	0.10	1.25
14	0.78	0.22	3.03	0.89	0.11	1.55
15	0.78	0.22	3.26	0.88	0.12	1.79

The rate of occurrences and expected number of simple TM helices are computed for 15 sets of UniProt-derived membrane entries grouped by the number of TM helices they contain. The number of TM helices for each set is given in column 1. Column pairs (2,3) and (5,6) gives the ratios of complex and simple TM helices found in each set based on the z-score thresholds of f = 1.282 (false-negative rate of 10%) and f = 1.645 (false-negative rate of 5%) respectively. Similarly, column 4 and 7 gives the expected number (No. of TMs × ratio of simple TMs) of simple TM helices in each set at those z-score thresholds.