Hi As a referee, if I had been supplied with data processing statistics that indicate there is good information going to a higher resolution than that used for refinement etc, I would want to know why the data had been cut off. "Making life easier" wouldn't cut the mustard, I'm afraid!
Clearly, the CC1/2 of 0.796 in the high resolution shell shows that there is good internal agreement to at least 1.05Å - this internal agreement is normally taken to mean that the data are "good to that resolution". The mean I/sd(I) is also quite high in the high resolution shell, which is also encouraging. I might be inclined to ask why the data were cut to such a low resolution of 1.05Å anyway... A quick back of the envelope calculation suggests that cutting back from 1.05 to 1.1Å is throwing away ~15% of the data (cutting back to 1.2Å throws away ~1/3 of the data). Not sure I'd want to do that without a really good justification. However, Michail Isupov raises a very important point; one of the things that I always teach when discussing "Table 1" is that the statistics for the low resolution shell should be the best, those for the high resolution shell should be the worst, and the overall statistics should be in between (but with luck and a following wind closer to those for the low resolution shell). Anything else indicates a problem either in the data collection or the data processing; with very high resolution data, the first things I would look at are possible overloads in the low resolution shell (in iMosflm there's a plot of the overloads which is not displayed by default but it's easy to turn it on...). The real answer involves looking at the data processing in detail before cutting out any data, as others have said. Maybe even taking some time to look at the diffraction images themselves. Overloading high I reflections (which tend to be at low resolution...) is very easy when chasing high resolution reflections, and is a reason to collect data in multiple passes to get the best measurements of both strong and weak reflections; it's something that used to be quite common amongst the people who collect good datasets. At least some lab-based small molecule instruments do multiple passes automatically. On 10 Oct 2018, at 11:13, Antonio Ariza wrote: > Hi Pavel, > > Obviously higher resolution typically means a more accurate atomic model of a > crystal structure, but I also think that a 1.05 Ang structure is only going > to provide you with a great deal more insight than a 1.1 or 1.2 Ang > structure in very specific cases. Particularly if your stats aren't > completely ideal , why not make sure you get the best possible stats out of > your data by slightly cutting the resolution, which is still going to leave > you with a VERY high resolution data set (at least I would consider 1.1 or > 1.2 Ang as very high resolution)? > > Please forgive my ignorance, but I have to admit I haven't researched this > topic. Is there something wrong with using TLS refinement coupled with > anisotropic refinement in Refmac? I just checked and I have found that TLS > still provides a small drop in the R factors when comparing anisotropic > refinement to TLS + anisotropic refinement in the 1.2 Ang data set I'm > currently working on. Ok, it's just under 0.5%, which I admit isn't a huge > change, but shouldn't I take any improvement I can get? > > Cheers, > > Tony > > ------------------------------------------------------ > > Dr. Antonio Ariza > University of Oxford > Sir William Dunn School of Pathology > South Parks Road > Oxford > OX1 3RE > e-mail: [email protected] > Tel: 00 +44 1865 285655 > > Links to my public profiles: > ResearchGate > LinkedIn > GoogleScholar > Twitter > > Check out my latest paper!!! > Structural insights into the function of ZRANB3 in replication stress response > > > > To unsubscribe from the CCP4BB list, click the following link: > https://www.jiscmail.ac.uk/cgi-bin/webadmin?SUBED1=CCP4BB&A=1 ######################################################################## To unsubscribe from the CCP4BB list, click the following link: https://www.jiscmail.ac.uk/cgi-bin/webadmin?SUBED1=CCP4BB&A=1
