Re: [ccp4bb] difference density ripples around Hg atoms

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CCP4bb <-- 2007 <-- August 2007 <-- 01 August 2007

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Subject: Re: difference density ripples around Hg atoms
From: Kay Diederichs Kay {- dot -} Diederichs {- at -} UNI-KONSTANZ {- dot -} DE
Date: 2007-08-01

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Subject: Re: difference density ripples around Hg atoms
From: Bart Hazes bart {- dot -} hazes {- at -} UALBERTA {- dot -} CA
Date: 2007-08-01

Subject: Re: difference density ripples around Hg atoms
From: Peter Adrian Meyer pam52 {- at -} CORNELL {- dot -} EDU
Date: 2007-08-01

You've most likely looked at this, but if not it might be worthwhile to
check how these ripples behave while varing the low-resolution limit used
(20-2.2,15-2.2, etc).

Pete

> Dear friends of the Fourier transform,
>
> I am refining a structure with 2 adjacent Hg atoms bound to cysteines of
> different monomers in the crystal contacts, which means I need to refine
> them as well. While the structure nicely refines (2.2 A data), I do not
> get rid of negative density ripple layers next to them (-10 sigmas). My
> question: is this likely due to anistropy of the soft mercury atoms
> (anisotropic B refinement decreases the ripples) or is this likely a
> summation truncation effect prominent for heavy atoms? Can I just
> anistropically refine the mercuries while I keep the rest isotropic?
> Never saw this in a PDB. Suggestions are very welcome.
>
> Greetings
>
> Klemens Wild
>

Pete Meyer
Fu Lab
BMCB grad student
Cornell University

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CCP4bb <-- 2007 <-- August 2007 <-- 01 August 2007

Previous message:
Subject: Re: difference density ripples around Hg atoms
From: Kay Diederichs Kay {- dot -} Diederichs {- at -} UNI-KONSTANZ {- dot -} DE
Date: 2007-08-01

Next message:
Subject: Re: difference density ripples around Hg atoms
From: Bart Hazes bart {- dot -} hazes {- at -} UALBERTA {- dot -} CA
Date: 2007-08-01