Hi Chenjun, Few suggestions from my side. Process the data with XDS and look into acentric intensity distribution (it indicates any twinning possibility). Run XTRIAGE and SFCHECK to understand any twinning or pseudo translation possibilities. Twinning can confuse the program and suggest you smaller unit cell with higher symmetry. Your images indicate longer cell axis. If you need more help, please send me an email.
Thank you Rajesh ---xxxxx---- With regards Rajesh K. Harijan, Ph.D. Schramm Laboratory Albert Einstein College of Medicine 1300 Morris Park Ave., Bronx, NY 10461 Tel: 718.430.2777 | Fax: 718.430.8565 On Thu, Jul 13, 2017 at 3:56 AM, 唐晨骏 <0910010...@cau.edu.cn> wrote: > hello everyone, > I would like to seek your opinion on my crystal hits. I am working on a > helicase > > of which the native structure is solved and the all solution statistics are > > fine. I am trying to crystallize and solve the structure of the > protein/ssDNA > > complex. I recently got some hits from commercial screens using sitting > drop > > vapor diffusion. After crystallization optimization, these crystals > diffract > > weakly but to 3.2 Angstroms for the longer exposure time. However, when the > > crystals rotate between 120 degrees to 180 degrees, the spots become > streaky > > (attached), no matter the crystals are hexagonal or flaky. I have tried to > > determine the structure by molecular replacement method, but the > Rwork/Rfree > > values are huge (above 0.5) and can’t be reduced further. I suspect the > > obtained crystals quality and resulting processed statistics is the reason > for > > the observed high Rwork/Rfree values. Are there any suggestions? > > All comments will be appreciated! > > Best, > Chenjun Tang > > >
