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> > > > 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 > > > >
