Order is like the curate's egg good in part! To reach 1A say PARTS of your crystal must be very stable, biut it can stillbe rather "sloppy" around the solvent boundary! Eleanor
On 28 November 2017 at 15:21, Matthew Merski <mer...@gmail.com> wrote: > Hi Alexandre, > > I was curious if I could also get a copy of the illustrations if it wont > be too much trouble? I was more curious about 0.0 - 4.0 Ang region if that > saves you some effort. > > Thank you for this. > > Matthew Merski > > On Tue, Nov 28, 2017 at 4:12 PM, Alexandre Ourjoumtsev < > alexander.ourjoumt...@univ-lorraine.fr> wrote: > >> Dear Vincent, >> >> first, certainly, you can continue to a higher resolutions distinguishing >> further details : >> >> 3.3 A - nucleic acid pairs >> .... >> 1.2 A - atomic details >> 0.9 A - deformation density >> (by the way, there was a relevant work, I think, by E.Blanc and >> G.Bricogne beginning of 2000, about some crucial high-resolution cut-offs). >> >> Second, a convenient scale for this detail analysis is logarithmic (we >> discussed this a few years ago in Acta Crsyt D); the limits you are talking >> about become more or less uniform in this scale. >> >> Third, at low resolution the situation is not at all so simple as you >> wrote. For example, images at 10-12 A may show neither "more ordered >> envelopes" nor "secondary structure elements" but only a "big mess". This >> is really the "worse resolution" to work with. I can send / give you >> off-list some illustrations. >> >> Best regards, >> >> Sacha Urzhumtsev >> >> ----- Le 28 Nov 17, à 15:44, vincent Chaptal <vincent.chap...@ibcp.fr> a >> écrit : >> >> Hi, >> >> I've been searching but can't find what I am looking for so I thought I >> ask specialists. >> >> I am curious about the link between resolution limits of reflections on >> the detector, and what features are ordered in real space. >> I saw the great movie by James Holton on resolution and features in the >> electron density map, but I am looking for something more general. >> I am thinking that a reflection on the detector originates from something >> ordered within the crystal. The level of order would be different at >> different resolution. >> >> If you can help me fill the void in this phrase: >> I see spots at __A resolution, therefore I know that _____ features are >> ordered in my crystal. >> >> intuitively, I would build the following scale: >> 20A : the envelope is ordered >> 10A: a finer envelope is ordered >> 6A: alpha helices are ordered >> 4-5A: beta sheets are ordered and some residues >> 3-4A: residues start to be ordered >> >3A: more and more order. >> >> Has this been described somewhere? I would appreciate any comments and >> reevaluation of this scale. >> >> Thank you in advance. >> All the best >> Vincent >> >> >> -- >> >> Vincent Chaptal, PhD >> >> Institut de Biologie et Chimie des Protéines >> >> Drug Resistance and Membrane Proteins Laboratory >> >> 7 passage du Vercors >> <https://maps.google.com/?q=7+passage+du+Vercors%C2%A0+69007+LYON+FRANCE&entry=gmail&source=g> >> >> <https://maps.google.com/?q=7+passage+du+Vercors%C2%A0+69007+LYON+%3Chttps://maps.google.com/?q%3D7%2Bpassage%2Bdu%2BVercors%25C2%25A0%2B69007%2BLYON%2BFRANCE%26entry%3Dgmail%26source%3Dg%3E+FRANCE+%3Chttps://maps.google.com/?q%3D7%2Bpassage%2Bdu%2BVercors%25C2%25A0%2B69007%2BLYON%2BFRANCE%26entry%3Dgmail%26source%3Dg%3E&entry=gmail&source=g> >> >> 69007 LYON >> <https://maps.google.com/?q=7+passage+du+Vercors%C2%A0+69007+LYON+FRANCE&entry=gmail&source=g> >> >> FRANCE >> <https://maps.google.com/?q=7+passage+du+Vercors%C2%A0+69007+LYON+FRANCE&entry=gmail&source=g> >> >> +33 4 37 65 29 01 <+33%204%2037%2065%2029%2001> >> >> http://www.ibcp.fr >> >> >> >> >
