Re: [ccp4bb]: big crystals that diffrct poorly

[Gerry McDermott <gmcdermott@lbl.gov>]

 Hi,

you should check out the Polymerase II structural paper [Cramer et al, Science (2001), 292, 1863-1876].  Initially, they had 6.0 Ang diffraction.  By  changing the composition of the post crystal growth mother liquor, the unit cell 'shrunk' by 11 Ang and the resolution limit increased to 3.0 Ang.  By adding Mn2+ or  other metal ions, the unit cell 'shrunk' by a further 8 Ang and the resolution limit increased to 2.6 Ang. 

Worth a try...

Cheers,

Gerry


On Thursday, May 9, 2002, at 10:53 AM, Jay Pandit wrote:

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> Hello all,
> Everyone has probably experienced this - big (0.5mmx0.5mmx0.3mm),
> beautiful crystals (sharp edges, clean faces), that diffract strongly to
> 6A, and no further. What's the reason for this ? Are there any stories
> out there of tricks that have improved the resolution of such crystals ? 
> This is not a ccp4-related topic, but then this bb is the best general
> crystallography discussion group that there is, so I have to post this
> question here ... 
> Jay
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> Jay Pandit
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