Table 2 The occurrence of π-turns with different conformational designations and the average backbone torsion angles (°) in the turn region
From: pi-Turns: types, systematics and the context of their occurrence in protein structures
Class | Cα-Cα distance (Å) | φi+1 | ψi+1 | φi+2 | ψi+2 | φi+3 | ψi+3 | φi+4 | ψi+4 |
|---|---|---|---|---|---|---|---|---|---|
Ï€-HB turns | |||||||||
AAAa (59%) | 5.4 (0.4) | -66 (9) | -33 (14) | -71 (13) | -36 (14) | -97 (15) | -6 (12) | 65 (16) | 38 (17) |
PgAA (9%) | 6.3 (0.7) | -62 (7) | 130 (7) | 85 (13) | -8 (17) | -113 (15) | -64 (17) | -101 (19) | -18 (19) |
AAAA (6%) | 5.8 (1.0) | -63 (9) | -24 (15) | -87 (15) | -15 (23) | -115 (18) | -71 (37) | -99 (26) | -18 (23) |
Schellman motif π-turns (SCH+β) | |||||||||
AAAa (98%) | 5.3 (0.4) | -65 (5) | -42 (6) | -63 (6) | -30 (8) | -90 (11) | 4 (10) | 76 (19) | 24 (17) |
Ï€-NHB turns | |||||||||
AEAA (11%) | 5.8 (0.5) | -85 (19) | -14 (19) | -101 (34) | 150 (22) | -62 (11) | -25 (13) | -89 (16) | -3 (17) |
EAAa (10%) | 5.3 (0.3) | -89 (15) | 179 (10) | -64 (9) | -20 (12) | -92 (12) | 4 (10) | 84 (13) | 11 (11) |
EAAA (8%) | 5.8 (0.5) | -94 (34) | 150 (24) | -58 (9) | -30 (12) | -80 (15) | -24 (18) | -110 (21) | -13 (21) |
EAAE (6%) | 4.8 (0.7) | -120 (28) | 177 (19) | -64 (11) | -28 (14) | -105 (19) | -16 (23) | -146 (22) | 144 (28) |
AAaA (6%) | 5.7 (0.4) | -67 (19) | -26 (17) | -92 (19) | -3 (13) | 74 (15) | 14 (18) | -96 (20) | -17 (19) |
AEEa (6%) | 5.8 (0.5) | -89 (19) | -12 (17) | -101 (31) | 144 (30) | -57 (8) | 134 (10) | 81 (16) | 2 (20) |