Is this another example of crystallising the reagent and not the desired material? No wonder molecular replacement failed with a DNA search model .
Eleanor On 25 April 2018 at 20:06, George Sheldrick <gshe...@uni-goettingen.de> wrote: > Dear Rafal et al, > > With some help from Kay I think that I could find out what is happening > here. SHELXT finds the space group Ibca and solves the structure easily > with default parameters but has difficulty in assigning the elements > because it was not expecting arsenic (!). The data are not very good but > it appears to be a cacodylate with five molecules in the asymmetric unit > and an unknown cation (K gave the best results). I could not find the > structure in the COD. I will send you the atom coordinates in a separate > file but the data would never get through CIFCheck (which you would need > to publish it in Acta E.). > > Best wishes, George > > > On 20.04.2018 15:30, Rafal Dolot wrote: > >> Dear CCP4BB, >> >> I've recently collected data for 11mer build of DNA (9xG, 2xT). XDS, and >> DIALS gave me similar solution - SG: I2(1)2(1)2(1) or I222, with cell >> dimension 20.65, 22.96, 43.37, 90, 90, 90, what is too small for this size >> of the molecule. 11mer is rich in G, so we expect the G-tetraplex >> formation. Data were collected to almost 1 A, so it should be enough for >> trials with direct methods/ab initio solution. What I should do first to >> find correct SG and/or cell parameters? >> >> Best regards, >> >> Rafal >> > > -- > Prof. George M. Sheldrick FRS > Dept. Structural Chemistry, > University of Goetti > <https://maps.google.com/?q=ity+of+Goetti&entry=gmail&source=g>ngen, > Tammannstr. 4, > D37077 Goettingen, Germany > Tel. +49-551-39-33021 or -33068 > Fax. +49-551-39-22582 >
