Acta Crystallographica Section D

Biological Crystallography

Volume 62, Part 8 (August 2006)

research papers

Acta Cryst. (2006). D62, 891-896 [ doi:10.1107/S0907444906010432 ]

From phasing to structure refinement in-house: Cr/Cu dual-wavelength system and a loopless free crystal-mounting method

N. Watanabe

Abstract: The practical applicability of in-house structure determination using Cr K [alpha] X-rays (2.29 Å) and a loopless free crystal-mounting method was examined using five novel proteins. Proteins from 9.6 to 84 kDa have been solved using this method without any derivatization. In all cases, more than 90% of structures were constructed automatically with side chains by use of the Cr SAD method. The free crystal-mounting technique increases the accuracy of the anomalous differences between Bijvoet mates and makes the in-house single-wavelength SAD method with a Cr K [alpha] X-ray source a very useful tool for high-throughput structure determination. In addition, a Cr/Cu dual-wavelength system makes it possible to perform structure analysis from phasing to refinement of the structure in-house.

Keywords: Cr radiation; SAD method; free crystal-mounting method.