Re: [ccp4bb] Puzzling electron density upon heavy metal soaking

2012-11-01 Thread Joern Krausze
Here is a snapshot of the anomalous map: http://imageshack.us/a/img560/1905/anomalousmap.png The map is contoured to 2.5sigma. They are the strongest peaks in the map. Not all 7 positions are equally strong. J. ** Address: Joern Krausze Molecular Stru

Re: [ccp4bb] Puzzling electron density upon heavy metal soaking

2012-11-01 Thread Joern Krausze
@Partha I have 4 polypeptide chains in the au. The density in the pictures is located between chain A and C'(symmetry mate of chain C), so it is not located on a special position I will prepare and attach a figure of the anomalous map a.s.a.p. In my memory there was density in all 7 position

Re: [ccp4bb] Puzzling electron density upon heavy metal soaking

2012-11-01 Thread Filip Van Petegem
Hello Joern, do you have an image of the anomalous difference map as well? Do you see the same 7 peaks there, or only the central blob? Filip On Thu, Nov 1, 2012 at 11:45 AM, Joern Krausze wrote: > Dear all, > > I have two isomorphous crystals of the same protein. One crystal, let's > call it

Re: [ccp4bb] Puzzling electron density upon heavy metal soaking

2012-11-01 Thread Dom Bellini
@JISCMAIL.AC.UK] on behalf of Joern Krausze [jk...@helmholtz-hzi.de] Sent: 01 November 2012 18:45 To: ccp4bb Subject: [ccp4bb] Puzzling electron density upon heavy metal soaking Dear all, I have two isomorphous crystals of the same protein. One crystal, let's call it 'derivative', was

Re: [ccp4bb] Puzzling electron density upon heavy metal soaking

2012-11-01 Thread Joern Krausze
Thank you for your efforts! @BR: Yes, I do have anomalous data which indicate that the density stems from Co(II) or anything else that shows significant anomalous dispersion at 1.6083 A. I just cannot picture 7 Co(II) ions forming a perfectly planar hexagonal structure with one Co(II) in the c

[ccp4bb] Puzzling electron density upon heavy metal soaking

2012-11-01 Thread Joern Krausze
Dear all, I have two isomorphous crystals of the same protein. One crystal, let's call it 'derivative', was soaked with 10 mM CoCl2 whereas the other, let's call it 'original', was not. Both crystals were otherwise grown under identical conditions (see below) and treated the same. In the derivati