Figure 26.1.2.13

Blake, C. C. F.; Fenn, R. H.; Johnson, L. N.; Koenig, D. F.; Mair, G. A.; North, A. C. T.; Oldham, J. W. H.; Phillips, D. C.; Poljak, R. J.; Sarma, V. R.; Vernon, C. A.

doi:10.1107/97809553602060000725

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

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International Tables for Crystallography (2006). Vol. F. ch. 26.1, p. 754 | 1 | 2 |

Figure 26.1.2.13

C. C. F. Blake,^a ^‡ R. H. Fenn,^a ^§ L. N. Johnson,^a ^*^¶ D. F. Koenig,^a ^‡‡ G. A. Mair,^a ^‡‡ A. C. T. North,^a ^§§ J. W. H. Oldham,^a ^¶¶ D. C. Phillips,^a ^¶¶ R. J. Poljak,^a ^‡‡‡ V. R. Sarma^a ^§§§ and C. A. Vernon^b ^¶¶

^a Davy Faraday Research Laboratory, The Royal Institution, London W1X 4BS, England, and ^bDepartment of Chemistry, University College London, Gower Street, London WC1E 6BT, England
Correspondence e-mail: louise@biop.ox.ac.uk

Figure 26.1.2.13

Views of a 6 Å resolution model of the regions in which the electron density exceeds about 0.53 e Å⁻³. The vertical rods indicate the twofold and fourfold screw axes parallel to c. The thinner horizontal rods are twofold rotation axes. At two places, shown hatched, rotation axes pass through continuous regions of density. The white regions alone make up the most compact asymmetric unit of the structure. In part (b), the grey section (B) is alternative to the region (A), to which it is related by the twofold axis T. In part (a), the grey section (D) is alternative to the white (C), related by the fourfold screw axis. The grey piece (F) in part (c) is alternative to the white (E), to which it is related by a unit-cell translation along c. The scale is indicated by the framework of symmetry elements, adjacent parallel twofold axes being 18.95 Å apart. Reproduced with permission from Nature (Blake et al., 1962). Copyright (1962) Macmillan Magazines Limited.