On Monday, 23 September, 2013 22:01:32 RHYS GRINTER wrote:
> Hi all,
>
> I have been attempting to find a MR solution for a low resolution data set (3.9A), with pretty poor merging stats of a 22 strand membrane beta barrel I'm working on.
>
> I've created a trimmed poly-alanine from a structure of 17% identity, that gives a solution with a Tfz of 14.3 with two molecules per asu (llg is around 900). I'm guessing this in a genuine solution, but the map is too poor to build into.
>
> Does anyone have any advice as to proceed from here? It may be just a case of needing better resolution data to work with, but would this indicate that Selenomet derivative crystals won't be needed for this structure?
Apart from whether you "need" SeMet for phasing, when you are having trouble fitting into
poor maps it can help a lot to have the location of methionines pinned down by peaks
in an anomalous difference Fourier map.
Ethan
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