International
Tables for
Crystallography
Volume F
Crystallography of biological macromolecules
Edited by M. G. Rossmann and E. Arnold

International Tables for Crystallography (2006). Vol. F. ch. 1.2, p. 7   | 1 | 2 |

Figure 1.2.5.2 

M. G. Rossmanna*

aDepartment of Biological Sciences, Purdue University, West Lafayette, IN 47907-1392, USA
Correspondence e-mail: mgr@indiana.bio.purdue.edu

[Figure 1.2.5.2]
Figure 1.2.5.2

Cylindrical sections through a helical segment of a myoglobin polypeptide chain. (a) The density in a cylindrical mantle of 1.95 Å radius, corresponding to the mean radius of the main-chain atoms in an α-helix. The calculated atomic positions of the α-helix are superimposed and roughly correspond to the density peaks. (b) The density at the radius of the β-carbon atoms; the positions of the β-carbon atoms calculated for a right-handed α-helix are marked by the superimposed grid (Kendrew & Watson, unpublished). Reprinted with permission from Perutz (1962[link]). Copyright (1962) Elsevier Publishing Co.