- which may well be caused by your cryo-protection or flash-cooling procedure. I'd try to collect a few images at room temperature to see how good the crystals can be and if this procedure can be improved. To prevent overlaps, it may help to find a way to collect the data with the crystal rotating around the most problematic cell axis, which tends to be the shortest in the crystal. Bent loops might be helpful.
Mark J van Raaij Dpto de Estructura de Macromoleculas Centro Nacional de Biotecnologia - CSIC calle Darwin 3 E-28049 Madrid, Spain tel. (+34) 91 585 4616 http://wwwuser <http://www.cnb.csic.es/~mjvanraaij>.cnb.csic.es/~mjvanraaij <http://www.cnb.csic.es/~mjvanraaij> > On 13 Jul 2017, at 11:13, Keller, Jacob <kell...@janelia.hhmi.org> wrote: > > You've got multiple lattices--try seeding approaches mentioned in a > recent/current thread. > > JPK > > -----Original Message----- > From: CCP4 bulletin board [mailto:CCP4BB@JISCMAIL.AC.UK] On Behalf Of ??? > Sent: Thursday, July 13, 2017 3:56 AM > To: CCP4BB@JISCMAIL.AC.UK > Subject: [ccp4bb] weird diffraction pattern > > 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 > >
