Sorry - meant to add this: I know that (of the “free” programs) Mosflm, DIALS and Eval15 can process multiple lattices.
Harry > On 28 Jul 2022, at 14:36, Harry Powell <hrp-ccp...@virginmedia.com> wrote: > > Hi Sayan > > If you have multiple lattices showing in your diffraction pattern, it may be > worthwhile using one of the programs that can process multiple lattices for > your integration. > > It may also be a good idea to share a few of your images that show the > problem with an expert (don’t post the images to ccp4BB!) who may be able to > offer you advice. > > Best wishes > > Harry > > >> On 28 Jul 2022, at 14:17, Sayan Saha <ssaha43...@gmail.com> wrote: >> >> Dear Sir, >> The crystal-to-detector distance was set to 190 mm. Yes, multiple >> diffractions seem to be present. We have not yet tried Zanuda on the P1 >> structure. However, the Rw/Rf of P1 structures are little higher (31/34%). >> >> With best regards, >> Sayan Saha. >> >> On Thu, Jul 28, 2022 at 5:22 PM Schreuder, Herman /DE >> <herman.schreu...@sanofi.com> wrote: >> Dear Sayan, >> >> >> >> Thank you for this information. Why are your spots overlapping? The axes of >> your crystal are not particularly long. Did you put the detector very close >> to the crystal, or are there multiple diffraction patterns? >> >> >> >> Did you run Zanuda on your P1 structure? What Rfactors do you get when you >> complete the refinement in P1? >> >> >> >> Best regards, >> >> Herman >> >> >> >> Von: Sayan Saha <ssaha43...@gmail.com> >> Gesendet: Donnerstag, 28. Juli 2022 11:43 >> An: Schreuder, Herman /DE <herman.schreu...@sanofi.com> >> Cc: CCP4BB@JISCMAIL.AC.UK >> Betreff: Re: [ccp4bb] Regarding the correct space group identification >> >> >> >> Dear Sir, >> >> >> >> 1. There are no ice-rings. However, diffraction spots seem to be >> overlapping. This can be seen during the data processing, as the space group >> (C2 or P222) varies even in the consecutive frames. >> >> >> >> 2. Crystal packing of C2 and P22121 seem to be similar (please see the >> attached images). >> >> >> >> 3. Forgot to mention in my previous email that we have already processed the >> data in P1 and MR solution could be found only in P1 (Phaser was used with >> an option in all possible space groups of that point group). >> >> >> >> Please let me know if any other information is required. >> >> >> >> With best regards, >> >> Sayan Saha. >> >> >> >> >> >> On Thu, Jul 28, 2022 at 1:26 PM Schreuder, Herman /DE >> <herman.schreu...@sanofi.com> wrote: >> >> Dear Sayan, >> >> >> >> If a subunit is correctly oriented, but the translation is incorrect, >> density for a ligand may still show up in the binding site of the protein. >> It might be that one of the 2-fold axes, you think is crystallographic, is >> in fact non crystallographic and a few Angstroms away from the >> crystallographic position. >> >> >> >> What I would do: >> >> • Check the images: are there ice-rings or other artifacts that could >> cause scaling problems that would lead to high Rw/Rf values? In that case, >> there is not much you can do. >> • Compare the C2 and P22121 solutions: do they have the same overall >> crystal packing (CS+NCS), or are they different? Do they have the same Rw/Rf >> values? Can we learn anything from the differences in overall crystal >> packing? >> • Process, run MR and refine in P1. Do you get lower R-factors? If so, >> then run Zanuda to find out the real space group. >> >> >> Best, >> >> Herman >> >> >> >> Von: CCP4 bulletin board <CCP4BB@JISCMAIL.AC.UK> Im Auftrag von Sayan Saha >> Gesendet: Donnerstag, 28. Juli 2022 08:15 >> An: CCP4BB@JISCMAIL.AC.UK >> Betreff: [ccp4bb] Regarding the correct space group identification >> >> >> >> Dear All, >> >> >> >> We have collected home-source X-ray intensity data for a protein at 2.6 >> Angstrom. The data can be processed in either C2 (a=120, b=80, c=85 and >> beta=115) or P222 (P22121, a=80, b=85, c=110). MR solution can be obtained >> in both the space groups. However, the solution can be refined with an Rw/Rf >> of 29/32% only. The protein is bound to a ligand (co-crystallization) for >> which a clear density can be observed. >> >> >> >> Any help and suggestion in this regard would be very helpful. >> >> >> >> With best regards, >> >> Sayan Saha. >> >> >> >> >> >> To unsubscribe from the CCP4BB list, click the following link: >> https://www.jiscmail.ac.uk/cgi-bin/WA-JISC.exe?SUBED1=CCP4BB&A=1 >> >> >> To unsubscribe from the CCP4BB list, click the following link: >> https://www.jiscmail.ac.uk/cgi-bin/WA-JISC.exe?SUBED1=CCP4BB&A=1 >> > ######################################################################## 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/
