If the foldamer(s) have exposed flexible parts they may impede ordered crystallisation. Perhaps some minor tweaks to the foldamer or foldamers you are co-crystallising with might lead to a better crystal contacts? For example removing one or a few residues from the end(s) or shortening a loop.
Mark J van Raaij Dpto de Estructura de Macromoleculas Centro Nacional de Biotecnologia - CSIC calle Darwin 3 E-28049 Madrid, Spain Section Editor Acta Crystallographica F https://journals.iucr.org/f/ > On 18 May 2021, at 12:08, Deepak Deepak <deepmalik...@gmail.com> wrote: > > Dear all, > > I have got multiple crystals (see picture 1) of a protein (8kDa) with a > helical aromatic oligoamide foldamer (5kDa) but these crystals diffract very > poorly (see the diffraction pattern in picture 2). > > I prepare a 1.3mM:1.3mM complex of protein: foldamer in 20mM Tris, pH 7.5 > buffer. Crystals grew in 3-5 days in sitting and hanging drop at 20 Deg C and > 25 Deg C in the following conditions: > > - 20% PEG 400, 0.1M MES pH 6.0 > -20% PEG 400, 0.1M Sodium Cacodylate pH 6.0 > > Multiple cryo used were: > -25%Glycerol in mother solution > -30% glycerol in water > -30%PEG 400, > -35% PEG 400 > -20% PEG 8000 + 40% PEG 400 mix > > Kindly suggest some methods/modifications on how can I improve the resolution > and get better-diffracting crystals. Please let me know if you need more > information. > > Kind regards, > Deepak > Ph.D. Student > > PS: The protein is a DNA binding protein and I have crystallized and solved > the structure of this protein with its DNA partner and now I crystallized it > with our foldamers but diffraction is not good. There are multiple structures > of the Protein+DNA complex in literature but no apo-protein structure as the > protein needs a binding partner to crystallize. We already have solution > studies showing a good binding. > > To unsubscribe from the CCP4BB list, click the following link: > https://www.jiscmail.ac.uk/cgi-bin/WA-JISC.exe?SUBED1=CCP4BB&A=1 > <https://www.jiscmail.ac.uk/cgi-bin/WA-JISC.exe?SUBED1=CCP4BB&A=1><Picture1,.png><Picture2.png> ######################################################################## To unsubscribe from the CCP4BB list, click the following link: https://www.jiscmail.ac.uk/cgi-bin/WA-JISC.exe?SUBED1=CCP4BB&A=1 This message was issued to members of www.jiscmail.ac.uk/CCP4BB, a mailing list hosted by www.jiscmail.ac.uk, terms & conditions are available at https://www.jiscmail.ac.uk/policyandsecurity/
