Hi Dusan, I am pretty sure
"It is well accepted that the criteria for resolution cutoff should consider both I/SigI and Rmerge for the outer most shell. For data sets collected at synchrotron sources, the criteria of I/SigI > 5 and Rmerge <50% can be taken as a good practical reference.” has been considered obsolete for a number of years - the efforts of many have shown that this is not good practice, including but not limited to Karplus & Diederichs - https://science.sciencemag.org/content/336/6084/1030.long The suggestion above is to throw away large amounts of almost certainly useful information, which cannot give rise to a better model Best wishes Graeme On 28 Feb 2020, at 08:22, dusan turk <dusan.t...@ijs.si<mailto:dusan.t...@ijs.si>> wrote: Hi, Browsing through the recent discussion on EM data resolution cutoff it occurred to me that the X-ray diffraction community isn’t that unanimous either. My stand: When the default resolution cutoff provided with the data processing software in electron density map calculation and refinement delivers quality maps noisier than expected and/or too high R-factors I start adjusting the resolution cutoff by lowering the resolution and trying alternative space group. Hence, I allow the data processing programs to suggest where to draw the line (be it CC1/2, I/sigI, R merge, R sym, R p.i.m. and R r.i.m, …) , unless there are problems. Doing so, I came into a dispute with a referee who shaped his request: "It is well accepted that the criteria for resolution cutoff should consider both I/SigI and Rmerge for the outer most shell. For data sets collected at synchrotron sources, the criteria of I/SigI > 5 and Rmerge <50% can be taken as a good practical reference.” So where do we stand? Which are the most objective criteria for resolution cutoff to be used in diffraction data processing? Which number of shells to use when calculating the statistics? Do we have a consensus? best wishes, dusan turk Dr. Dusan Turk, Prof. Head of Structural Biology Group http://stef.ijs.si/ Head of Centre for Protein and Structure Production Centre of excellence for Integrated Approaches in Chemistry and Biology of Proteins, Scientific Director http://www.cipkebip.org/ e-mail: dusan.t...@ijs.si phone: +386 1 477 3857 Dept. of Biochem.& Mol.& Struct. Biology fax: +386 1 477 3984 Jozef Stefan Institute Jamova 39, 1 000 Ljubljana,Slovenia Skype: dusan.turk (voice over internet: www.skype.com ######################################################################## To unsubscribe from the CCP4BB list, click the following link: https://www.jiscmail.ac.uk/cgi-bin/webadmin?SUBED1=CCP4BB&A=1 -- 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 ######################################################################## To unsubscribe from the CCP4BB list, click the following link: https://www.jiscmail.ac.uk/cgi-bin/webadmin?SUBED1=CCP4BB&A=1
