1. Helix Geometry in Proteins
D. J. Barlow and J. M. Thornton
Department of Crystallography
Birkbeck College London
J.Molec.Biol. (1988) 201,

2. general analysis of 291 helices
the 310-helix
“ideal” pauling model. : -74, : -4
figure 2. ,  angles of 310-helices
averaged model. : -71, : -18

3. analysis of the regularity and curvature of 48 -helices using HBEND
Rl : r.m.s deviation of axis points from a line
Rc : r.m.s.d. of axis
from a circle
radius of curvature
figure 5. helix curvature and regularity
(a) (b) (c )

5. the helices (figures 6, 8 and 9)
linear
kinked
irregular
 / 
: # res./turn
r.m.s.e.

6. figure 13
avian pancreatic peptide (aPP)
rad:68A, Rc:0.08A, Rl:0.37A
solvent face
hydrophobic packing

7. proline and the -helix
o i+4
o i+3
n i
n i+1
citrate synthase.
residues , =28˚
(figures 11 and 13)-helix