Table 3.

Overview of common interfaces.

	#Family	#CFGs	#Entry	In PDB (%)**	In PQS (%)	In PISA (%)	In ASU (%)
Single-domain Structures	1377	8816	19842	-	-	-	-
≥2 CFGs/Family	1125	8564	19446	-	-	-	-
≥2 CFGs/Cluster	868	6292	15264	-	-	-	-
N/N (N ≥ 4)	176	1372	3139	90	95	97	58
1>M/N > 0.7 (N ≥ 4)	74	676	1781	88	91	93	61
N/N (N = 2, 3)	266	618	1049	70	76	80	52
M ≥ 4 (M/N ≥ 0.5)*	248	2136	5200	89	93	95	59

^*From the analysis of Ponstingl/Bahadur benchmark set and NMR structures, M ≥ 4 and M/N ≥ 0.5 is most likely to be biological interest.

^**% in PDB, PQS, PISA and ASU are based on clusters, may have duplicate entries. NMR entries are excluded.