Appendix 1—table 3. Pi-pi contact enrichment for catalytic residues.

Frequency of involvement in contacts, at either backbone or sidechain sp² groups, is shown for individual residue types, residue independent (ANY), and residue type normalized (AVG), where catalytic residue contact frequency shows values for residues annotated as catalytic in the catalytic site atlas (Furnham et al., 2014) and non-catalytic residue contact frequency shows values for all other residues in the same structures. To normalize for possible differences in the number of contacts made by catalytic residues we also show number of pi-pi contacts divided by total number of VDW contacts, labeled as percent of VDW, and the percent of VDW ratio shows enrichment by dividing the catalytic percent of VDW value by the non-catalytic value. Error values are obtained by our standard bootstrap analysis (see Materials and methods), and enrichment values of greater than two standard deviations are shown in bold.

Residue type	Non-catalytic contact frequency (%)	Catalytic residue contact frequency (%)	N catalytic	Enrichment	Non-catalytic percent of VDW (%)	Catalytic residue percent of VDW (%)	Percent of VDW ratio (cat./non)
ANY	13.1 ± 0.1	24.5 ± 0.9	2914	1.87 ± 0.07	1.91 ± 0.09	3.94 ± 0.40	2.06 ± 0.23
HIS	31.9 ± 0.9	35.9 ± 2.3	471	1.12 ± 0.06	3.01 ± 0.26	4.33 ± 0.84	1.45 ± 0.31
ASP	12.9 ± 0.5	21.2 ± 2.0	448	1.65 ± 0.14	1.71 ± 0.22	3.08 ± 0.81	1.83 ± 0.54
GLU	11.7 ± 0.4	32.2 ± 2.5	370	2.75 ± 0.18	2.44 ± 0.31	6.57 ± 1.38	2.74 ± 0.71
ARG	26.7 ± 0.8	30.3 ± 3.2	287	1.14 ± 0.12	1.77 ± 0.29	7.85 ± 1.48	4.57 ± 1.26
LYS	6.2 ± 0.4	9.7 ± 2.0	259	1.56 ± 0.35	0.82 ± 0.20	0.37 ± 0.37	0.48 ± 0.52
TYR	36.1 ± 1.2	30.4 ± 3.7	171	0.84 ± 0.10	2.69 ± 0.39	4.62 ± 1.38	1.75 ± 0.59
SER	8.8 ± 0.5	13.0 ± 2.6	169	1.48 ± 0.28	0.83 ± 0.23	1.39 ± 0.70	1.84 ± 1.20
CYS	8.5 ± 1.3	14.7 ± 2.9	150	1.73 ± 0.26	1.45 ± 0.33	0.92 ± 0.66	0.68 ± 0.54
ASN	18.9 ± 1.1	26.6 ± 4.3	109	1.41 ± 0.20	1.88 ± 0.42	6.11 ± 1.76	3.42 ± 1.29
GLY	12.0 ± 0.7	16.2 ± 4.5	99	1.35 ± 0.41	1.26 ± 0.48	5.87 ± 1.92	5.72 ± 4.33
THR	6.8 ± 0.6	4.7 ± 2.3	86	0.69 ± 0.38	0.34 ± 0.18	0.88 ± 0.87	3.42 ± 4.17
GLN	18.0 ± 1.6	40.3 ± 7.3	62	2.24 ± 0.34	3.12 ± 0.53	1.88 ± 1.30	0.61 ± 0.44
ALA	7.8 ± 0.9	7.0 ± 3.3	57	0.91 ± 0.48	0.85 ± 0.43	1.28 ± 1.28	2.04 ± 2.75
PHE	34.2 ± 2.1	35.9 ± 7.1	53	1.05 ± 0.23	2.52 ± 0.64	4.92 ± 2.39	2.10 ± 1.27
TRP	46.2 ± 3.2	45.1 ± 7.5	51	0.98 ± 0.14	3.57 ± 0.73	2.88 ± 2.00	0.87 ± 0.68
AVG	18.7 ± 0.4	24.2 ± 1.2	N/A	1.42 ± 0.07