Dear Kevin You could try reindexing into P1, then run Phaser and with its solution as input to Zanuda determine the space group. Best wishes, John
Emeritus Professor of Chemistry John R Helliwell DSc_Physics > On 31 May 2019, at 21:09, Kevin Jude <[email protected]> wrote: > > Hello community, I wonder if I could solicit advice about a problematic > dataset. I plan to solve the structure by molecular replacement and expect > that the protein is relatively compact, ie not elongated. SAXS data supports > this expectation. > > The crystals diffract to 2.6 Å resolution and appear to be in P 21 21 2 with > a = 49, b = 67, c = 94, which should fit <=2 molecules in the ASU with 40% > solvent. The native Patterson shows a large peak (12 sigma) suggesting a tNCS > vector of {0.5, 0.5, 0}. > > If you're sharper than me, you may have already spotted the problem - c is > the long axis of the unit cell, but tNCS constrains the proteins to a plane > parallel to the a,b plane. Indeed, molecular replacement attempts using > Phaser will not give a solution in any orthorhombic space group unless I turn > off packing, and then I get large overlaps in the a,b plane and huge gaps > along c. > > Since I believe that my model is good (or at least the correct shape, based > on SAXS), I wonder if I'm misinterpreting my crystallographic data. Any > insights into how to approach this problem would be much appreciated. > > -- > Kevin Jude, PhD > Structural Biology Research Specialist, Garcia Lab > Howard Hughes Medical Institute > Stanford University School of Medicine > Beckman B177, 279 Campus Drive, Stanford CA 94305 > Phone: (650) 723-6431 > > > To unsubscribe from the CCP4BB list, click the following link: > https://www.jiscmail.ac.uk/cgi-bin/webadmin?SUBED1=CCP4BB&A=1 ######################################################################## To unsubscribe from the CCP4BB list, click the following link: https://www.jiscmail.ac.uk/cgi-bin/webadmin?SUBED1=CCP4BB&A=1
