[ccp4bb] Looking for heated goniometer heads

I'm wondering if anyone has any still-functioning heated goniometer heads that they no longer need. If so, please let me know offline from the list. Thanks, Chris __ DR. CHRISTOPHER A. WADDLING, PHD Crystallography Facility Manager University of California,

Re: [ccp4bb] X-rays gas scattering picture needed

I put some pictures of scattering from random things (including "air") here: http://bl831.als.lbl.gov/~jamesh/pickup/images/ It is actually more difficult than you might think to get a clean image of "air scatter" on a well-maintained camera. This is because we usually try to minimize the contr

Re: [ccp4bb] Xtal formed during purification

Dear Zhizhi, we had a case like that. I would switch to slightly different buffer (e.g. different pH) so crystals do not appear overnight, and then do crystallisation screening. I bet you will have many hits in different conditions, likely with bigger crystals. Good luck! Best wishes, Tomas On

[ccp4bb] Xtal formed during purification

Hi all, After I purified my target protein by ion exchange, I left the fractions with high protein concentrations overnight @4C. Now I saw a lot of small needle crystals inside the EP tubes this morning. I wonder whether there is any technique or method to get bigger crystals from this? ZZ

Re: [ccp4bb] 3-way obligatory associating proteins

An easy example is heterotrimeric G-proteins. In the termination cycle, G-alpha bound to GTP will hydrolyze the GTP, which then allows it to associate again with the G-beta/G-gamma dimer. Many membrane receptors (GPCRs, Chemotaxis, etc) can oligomerize and can be viewed like this, i.e., one dim

[ccp4bb] TLS update

Dear all, Thanks again for all the suggestions. I should perhaps add that I am working on glycosylated proteins and they which tend to be quite flexible in some areas. The website suggested by Ethan: http://skuld.bmsc.washington.edu/parvati did not show any areas that appeared alarming, or at

[ccp4bb] 3-way obligatory associating proteins

Hi CCP4BB members, I was wondering if anyone knows of examples of 3-way obligatory associating complexes. In other words, instead of having protein A binding to protein B and protein B also binding to protein C, example of complexes where protein C binds ONLY when proteins A and B are already asso

Re: [ccp4bb] Substrate/Ligand Induced Oligomerization of enzymes

Hi Shiva, There are some other enzyme systems activated by ligand induced oligomerization in addition to the ones on this list: 1) DNA polymerase dimerization on DNA binding 2) Restriction enzyme dimerization on DNA binding (an example is the type IIs FokI) 3) membrane enzyme receptors like rec

Re: [ccp4bb] Substrate/Ligand Induced Oligomerization of enzymes

Dear All, Thank you for your responses. Below is the compiled list of examples of substrate/ligand/co-factor induced oligomerization: http://www.pnas.org/content/97/13/7096.full.pdf http://www.ncbi.nlm.nih.gov/pubmed/15710608 http://www.ncbi.nlm.nih.gov/pubmed/17725819 http://www.ncbi.nlm.nih.gov/

Re: [ccp4bb] TLS refinement and ANISOU records

Hi Tim, no, in the cases I remember there was no significant difference in geometry - of course, we do tend to work on rather stable, rocky proteins... Mark On 9 Aug 2013, at 16:33, Tim Gruene wrote: > -BEGIN PGP SIGNED MESSAGE- > Hash: SHA1 > > Hi Mark, > > does your experience also

Re: [ccp4bb] TLS refinement and ANISOU records

-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 Hi Mark, does your experience also include the geometry of the model? There might be improvements, as e.g. reported from molprobity, because of a better modelling of the temperature factors. I am asking because you mention improvements of the electro

Re: [ccp4bb] TLS refinement and ANISOU records

Omid, how necessary is it that you do TLS refinement? I.e. are you just doing it to improve your Rs a bit or is the density really getting better? If the density is not improving, I would just refine without TLS and avoid any posterior temperature factor analysis difficulties. While I am sure th

[ccp4bb] Sponsored) access to the integrated facility for structural biology at EMBL Hamburg

Dear all, the integrated facility at EMBL Hamburg at the PETRA3 synchrotron in Germany consists of two macromolecular crystallography beamlines, a BioSAXS beamline and a laboratory for sample preparation and characterization. For those of you who are interested in a comprehensive characterizatio

Re: [ccp4bb] Substrate/Ligand Induced Oligomerization of enzymes

If you are willing to include cofactor-induced oligomerization instead of substrate-induced, how about imidazoleglycerol-phosphate dehydratase (IGPD) ? Inactive trimer: 1RHY http://www.ncbi.nlm.nih.gov/pubmed/14724278 Active 24-mer in presence of Mn2+ ions: 2F1D http://www.ncbi.nlm.nih.go