Re: [ccp4bb] Finding best model for molecular replacement

I recently used an ensemble of many proteins with Phaser. A single model did not find a solution but this ensemble of seven very similar molecules gave a correct solution with a TFZ of ~9.0. I did not trim the side chains in this ensemble (first try worked) but this introduced variation may be

[ccp4bb] Se-met protein as soluble aggregate

Dear All, I am trying to generate my protein with Se-Met incorporation. The purification protocol involves Ni-NTA followed by anion exchange followed by gel-filtration. The native protein behaves well and on gel filtration there is very little protein eluting at the void (s-200 column) with

Re: [ccp4bb] Se-met protein as soluble aggregate

, 2010 6:17 PM To: Joyce, Gordon M. (NIH/NIAID) [F] Subject: Re: [ccp4bb] Se-met protein as soluble aggregate Hi Gordon, You may have to give us more details about your protein. I would first ask you in what host (Ecoli, yeast ...) are you expressing your protein and how many methionines do you have

Re: [ccp4bb] Expression of a protein of 43KDa

You should mass spec your samples to determine what has crystallized, possible e coli contaminant. M. Gordon Joyce, Visiting Fellow, Structural Immunology Section, Laboratory of Immunogenetics, NIH/NIAID, 12441 Parklawn Drive, Rockville, MD 20851 Phone: 301 594 0242 Office 301

Re: [ccp4bb] OT: Crystallisation compatible detergents

Dear All, I found this paper quite informative on the procedure for screening and selecting detergents for protein crystallization. http://journals.iucr.org/d/issues/2005/04/00/sx5021/sx5021.pdf Best wishes, Gordon M. Gordon Joyce, Visiting Fellow, Structural Immunology Section,

Re: [ccp4bb] Heavy Atom Derivative Site

Hi Nilofer, We have just published a paper in Acta Cryst D which gives some of this information. Agniswamy J, Joyce MG, Hammer CH, Sun PD. Towards a rational approach for heavy-atom derivative screening in protein crystallography. Acta Cryst. (2008). D64, 354-367

[ccp4bb] heavy atom source summary

Thank you for the many useful replies which resulted in finding sources for these two compounds. methylmercury acetate at Pfaltz Bauer Trimethyllead acetate at Chemos GmbH Still at a loose end for a commercial source for the Triethyllead acetate though. It used to be carried

[ccp4bb] summary: heavy metal source update

So got the triethyl lead acetate. Thanks again to everyone. Gordon triethyl lead acetate by it's trickier name Acetoxytriethyllead(IV): http://www.sigmaaldrich.com/catalog/search/ProductDetail/ALDRICH/116823

[ccp4bb] heavy metal source

I am trying to locate a source for the following heavy atom compounds. Trimethyl lead acetate Triethyl lead acetate Methylmercury acetate Any suggestions would be greatly appreciated. I have checked the usual suspects but haven't found anything as yet. Yours, M. Gordon Joyce,

[ccp4bb] phasing power ofatoms

Hello everyone, I would like to know the phasing power of different heavy atoms ie how many seleniums per 10 kDa would be good enough to solve the structure. I wonder is there a good website or some useful publications that people know of, that would give this information, not just for