Table 1:

Distance-per residue values for secondary-structure bounded loops

Loop length	Helix-loop-helix (Mean)	Helix-loop-helix (SD)	Sheet-loop-sheet (Mean)	Sheet-loop-sheet (SD)	Sheet-loop-helix & helix-loop-sheet (Mean)	Sheet-loop-helix & helix-loop-sheet (SD)
1	3.81	0.027	3.81	0.027	3.809	0.067
2	3.036	0.284	3.19	0.313	3.137	0.278
3	2.836	0.397	1.846	0.293	2.818	0.361
4	2.511	0.441	1.607	0.469	2.482	0.418
5	2.275	0.483	1.274	0.419	2.154	0.45
6	2.178	0.499	1.14	0.474	1.928	0.448
7	2.026	0.504	1.139	0.49	1.749	0.455
8	1.876	0.537	1.198	0.505	1.67	0.436
9	1.835	0.534	1.177	0.447	1.531	0.452
10	1.669	0.538	1.115	0.501	1.428	0.438
11	1.658	0.545	1.029	0.475	1.377	0.416
12	1.666	0.507	1.048	0.479	1.282	0.407
13	1.625	0.494	0.935	0.417	1.261	0.402
14	1.53	0.468	0.91	0.451	1.203	0.411
15	1.445	0.447	0.908	0.416	1.135	0.405
16	1.374	0.428	0.85	0.373	1.045	0.381
17	1.292	0.439	0.83	0.395	1.004	0.378
18	1.212	0.415	0.852	0.47	1.02	0.373
19	1.164	0.432	0.849	0.418	0.977	0.36
20	1.133	0.392	0.761	0.36	0.928	0.372
21	1.049	0.382	0.722	0.349	0.865	0.338
22	1.043	0.38	0.742	0.359	0.834	0.322
23	1.074	0.401	0.684	0.312	0.811	0.308
24	0.977	0.381	0.677	0.302	0.756	0.285
25	0.965	0.38	0.611	0.281	0.761	0.289
26	0.938	0.317	0.587	0.279	0.749	0.296
27	0.868	0.328	0.596	0.264	0.777	0.298
28	0.824	0.304	0.565	0.259	0.74	0.294
29	0.805	0.318	0.576	0.346	0.655	0.286
30	0.788	0.273	0.532	0.257	0.648	0.208

The mean and standard deviation of the distance-per-residue for loops based on number of residues and bounding secondary structure element was determined from the CATH S100 database as described in [2.1.4]. Helix-loop-helix and sheet-loop-sheet values were computed using 1,668,774 and 614,152 Smotif elements, respectively. Sheet-loop-helix and helix-loop-sheet observations were combined, with a total of 1,416,244 Smotif elements (702,557 sheet-loop-helix and 713,687 helix-loop-sheet) used to compute the values.