Hmm - that sym op means you have a near C centred cell with spacegroup C 2 2 2 ?
Maybe some of your protein has been chewed up? That does happen? How good is the diffraction? Eleanor On Sat, 1 Jun 2019 at 17:44, Jonathan Cooper < 00000c2488af9525-dmarc-requ...@jiscmail.ac.uk> wrote: > Does the SAXS model contain more than one subunit? If so, I would be > tempted to go back to the model and try each one separately. This may not > apply, but if there are monomers in the SAXS model that are related by > space group symmetry in the crystal, I think the MR would never work. Good > luck with it! Bests, Jon. Cooper > > Sent from Yahoo Mail on Android > <https://go.onelink.me/107872968?pid=InProduct&c=Global_Internal_YGrowth_AndroidEmailSig__AndroidUsers&af_wl=ym&af_sub1=Internal&af_sub2=Global_YGrowth&af_sub3=EmailSignature> > > On Sat, 1 Jun 2019 at 9:45, Jrh Gmail > <jrhelliw...@gmail.com> wrote: > 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 <kj...@stanford.edu> 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 > > > ------------------------------ > > 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
