Rafal, Unit cell parameters: if you look at the images, and all the reflections are integrated, you should see little blue boxes & no missed reflections - if this is correct then the P1 unit cell is probably correct
Regarding the space group: for this case you may find NCS confusing the symmetry determination routines so I would take the outcome with a pinch of salt, but it could be that you have something different to what you expect. With this resolution you could probably solve it in P1 and work out the symmetry a posteri. I have solved structures of DNA in the past with SHELXT but this was (i) small and (ii) made the computer sweat. Re: I222/I212121 you cannot tell the difference from systematic absences i.e. what POINTLESS does. If XSD and DIALS give a similar solution and the reflections are all integrated, then on the balance of probability I would guess the answer is correct i.e. PG 222 and body centred, but only probably - some one will always come up with exceptions As someone said earlier this week - you only know the symmetry once you’ve refined the structure Best wishes Graeme > On 20 Apr 2018, at 14:30, Rafal Dolot <rdo...@cbmm.lodz.pl> 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 > -- > |----------------------------------------------| > |Rafal Dolot, Ph.D. | > | | > |Polish Academy of Sciences | > |Centre of Molecular and Macromolecular Studies| > |Department of Bioorganic Chemistry | > |Macromolecular Crystallography Team | > |Sienkiewicza 112 | > |90-363 Lodz, Poland | > |Phone: +48(42)6803215 | > |Cell: +48 502897781 | > |----------------------------------------------| -- This e-mail and any attachments may contain confidential, copyright and or privileged material, and are for the use of the intended addressee only. If you are not the intended addressee or an authorised recipient of the addressee please notify us of receipt by returning the e-mail and do not use, copy, retain, distribute or disclose the information in or attached to the e-mail. Any opinions expressed within this e-mail are those of the individual and not necessarily of Diamond Light Source Ltd. Diamond Light Source Ltd. cannot guarantee that this e-mail or any attachments are free from viruses and we cannot accept liability for any damage which you may sustain as a result of software viruses which may be transmitted in or with the message. Diamond Light Source Limited (company no. 4375679). Registered in England and Wales with its registered office at Diamond House, Harwell Science and Innovation Campus, Didcot, Oxfordshire, OX11 0DE, United Kingdom
