IUCr journals

A modified ACORN to solve protein structures at resolutions of 1.7 Å or better

Acta Cryst. (2005). D61, 1465–1475 [doi:10.1107/S090744490502576X]

[ACORN F map] ACORN F map with observed data to 1.5 Å (red) and E map with data artificially extended to 1.0 Å (blue) for 1uuq.
ACORN is a procedure for determining protein structures from small fragments with data to better than 1.3 Å resolution. A modified ACORN now gives atomic-resolution protein solutions with observed data resolution as low as 1.7 Å. Data are artificially extended to 1 Å resolution, assuming that all extended data have |E| = 1. Additionally, improved density modification techniques are employed that are particularly effective in developing weak, but true, density. ACORN gives atomic-resolution maps that are easily traced and can be used to build structures automatically.

Yao Jia-xing, M. M. Woolfson, K. S. Wilson and E. J. Dodson