Well - you dont give details o f resolution but the sovent content and the peak of 0.51 would suggest a possible dimer in crystal 1
Crystal 2 is so different it might well have a dimer in a different orientation. I would try to see if there was a relationship between Xtal 1 and Xtal 2 - can tell you how I would do that if you are interested.. But doesnt mass spec or some such technique suggest whether there is a dimer or not? Eleanor Self Rotation Functions are a) hard to interpret and b) often misleading! On 31 May 2017 at 14:18, vincent Chaptal <vincent.chap...@ibcp.fr> wrote: > Dear all, > > I need help interpreting results from a SRF; I am very naïve at > interpreting them and would appreciate any pointer... > > I have 2 crystals, before and after additive during crystallogenesis. They > have different cell parameters, and I am wondering if I have a monomer or a > dimer in the ASU, and if the additive changed this. > > *crystal w/o additive:* > P21 114,5 107,6 134,6 beta=95,74 > 1monomer in the ASU = 80% solvent, 1 dimer in the ASU = 61% solvent. Note > that this high solvent content agrees well with the fact that this is a > membrane protein, and diffracts both to low resolution and very > anisotropic... > SRF from Molrep: > > +------------------------------------------+ > > | theta phi chi P(i)/P(0)| > > +------------------------------------------+ > > | 1 0.00 0.00 0.00 1.00 | > > | 2 148.48 0.00 180.00 0.51 | > > | 3 161.29 0.00 180.00 0.31 | > > | 4 105.34 180.00 180.00 0.30 | > > | 5 74.78 -56.26 179.58 0.27 | > > | 6 15.14 -163.78 180.00 0.25 | > > | 7 67.61 -40.16 180.00 0.24 | > > | 8 134.54 -180.00 180.00 0.19 | > > | 9 72.33 -37.82 180.00 0.18 | > > | 10 69.72 38.92 175.62 0.18 | > > | 11 110.28 -141.08 175.62 0.18 | > > | 12 96.58 101.90 179.79 0.18 | > > | 13 67.04 -15.02 179.71 0.18 | > > | 14 62.76 -15.52 179.45 0.17 | > > | 15 117.26 164.48 179.45 0.17 | > > | 16 68.39 -18.92 179.86 0.17 | > > | 17 70.52 -16.51 180.00 0.17 | > > | 18 24.05 -162.02 179.98 0.17 | > > | 19 78.61 -36.36 180.00 0.17 | > > | 20 83.17 78.42 173.34 0.16 | > > | 21 96.83 -101.58 173.34 0.16 | > > | 22 81.25 -75.03 179.73 0.16 | > > | 23 81.81 -17.73 180.00 0.16 | > > | 24 11.02 -142.22 180.00 0.16 | > > | 25 76.14 -16.64 179.71 0.16 | > > | 26 76.56 -16.93 180.00 0.16 | > > | 27 162.29 32.44 180.00 0.16 | > > | 28 10.03 -136.82 180.00 0.15 | > > | 29 68.67 -58.10 179.49 0.15 | > > | 30 111.33 121.90 179.49 0.15 | > > | 31 62.99 -20.19 180.00 0.14 | > > | 32 97.24 145.00 179.78 0.14 | > > | 33 99.56 165.86 179.74 0.14 | > > | 34 84.27 -82.68 180.00 0.14 | > > | 35 84.51 72.76 174.42 0.13 | > > +------------------------------------------+ > > > > Crystal with additive: > P21 > > CELL 117.2840 110.3330 155.6880 90.0000 93.4280 90.0000 > > 1 monomer in the ASU = 84% solvent, 1 dimer = 68% solvent. > > SRF from Molrep: > > +------------------------------------------+ > > | theta phi chi P(i)/P(0)| > > +------------------------------------------+ > > | 1 0.00 0.00 0.00 1.00 | > > | 2 59.55 0.00 180.00 0.36 | > > | 3 156.11 0.00 180.00 0.29 | > > | 4 10.00 -165.58 180.00 0.26 | > > | 5 110.22 -180.00 180.00 0.26 | > > | 6 12.97 -169.15 180.00 0.23 | > > | 7 166.21 -9.06 180.00 0.22 | > > | 8 81.64 -9.61 179.74 0.21 | > > | 9 86.02 80.72 178.22 0.20 | > > | 10 93.98 -99.28 178.22 0.20 | > > | 11 5.96 -54.00 180.00 0.19 | > > | 12 67.40 -10.81 180.00 0.19 | > > | 13 87.10 -94.56 179.91 0.19 | > > | 14 147.13 47.70 10.71 0.19 | > > | 15 147.13 -47.70 10.71 0.19 | > > | 16 87.45 91.04 155.74 0.19 | > > | 17 92.55 -88.96 155.74 0.19 | > > | 18 5.33 -63.00 180.00 0.19 | > > | 19 104.60 169.61 179.59 0.19 | > > | 20 88.01 -85.32 179.05 0.18 | > > | 21 92.02 94.64 179.68 0.18 | > > | 22 87.61 91.31 153.16 0.18 | > > | 23 92.39 -88.69 153.16 0.18 | > > | 24 6.65 -46.80 180.00 0.18 | > > | 25 153.26 36.01 21.16 0.18 | > > | 26 153.26 -36.01 21.16 0.18 | > > | 27 63.11 -11.30 179.51 0.18 | > > | 28 76.82 -5.09 179.61 0.18 | > > | 29 87.69 91.37 148.72 0.18 | > > | 30 92.31 -88.63 148.72 0.18 | > > | 31 86.74 -9.44 179.90 0.17 | > > | 32 85.83 80.82 148.49 0.17 | > > | 33 94.17 -99.18 148.49 0.17 | > > | 34 175.25 57.61 180.00 0.17 | > > | 35 4.63 -90.00 180.00 0.17 | > > +------------------------------------------+ > > > Can I say that the peak at 0.51 in the crystal without additive is > significant, concluding that there is probably a dimer in the ASU in that > crystal, in contrast to the crystal with additive where no peak stands out, > which would lean towards a monomer in the ASU? > > Thank you for your help. > Best > Vincent > > > > -- > > Vincent Chaptal, PhD > > Institut de Biologie et Chimie des Protéines > > Drug Resistance and Membrane Proteins Laboratory > > 7 passage du Vercors > > 69007 LYON > > FRANCE > > +33 4 37 65 29 01 <+33%204%2037%2065%2029%2001> > > http://www.ibcp.fr > >
