As far as I know there are several bumps: around 3.5-4 (there are some at low resolution related with molecular shapes also) - secondary structures, ~2.2 related with angles and around 1.2 related with covalent bonds. For DNA/RNA there is one more bump around 1.6-1.7 ( I thought that is because of Phosphor bonds). They are visible with normalised data better. I think there was a paper by Morris and Bricogne in Acta Cryst about these things.
These bumps have some consequences - B values calculated using Wilson plot usually jump up and dow around these bumps. Garib On 9 May 2012, at 19:44, Nat Echols wrote: > On Wed, May 9, 2012 at 11:35 AM, Edward A. Berry <ber...@upstate.edu> wrote: >> Still I would expect to see peaks in a wilson plot around bond-length >> resolution, similar to the peaks due to secondary structure at lower >> resolution. > > I was curious about this myself, so I looked at the Wilson plot for an > atomic-resolution structure (attached). There is at best a small hump > around 1.5A; I suspect uncertainties in atomic positions (i.e. the > B-factor) reduce the effect. This was consistent in several other > atom-resolution datasets (of different proteins). I'm curious what > the bump around 2.25A is. > > -Nat > <wilson_highres.png> Dr Garib N Murshudov Group Leader, MRC Laboratory of Molecular Biology Hills Road Cambridge CB2 0QH UK Email: ga...@mrc-lmb.cam.ac.uk Web http://www.mrc-lmb.cam.ac.uk
