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Hi Francisco,
There are many suggestions, but the most obvious answer is that maybe
you only have 10 copies in the ASU? You don't mention your beta angle but 10
copies would mean a solvent content of ~75%... Which is pretty high but not
impossible...
1) Did you check your maps? Do you have difference map density for extra
molecules?
2) Is the lattice believable (sensible and complete lattice contacts)?
3) How about your R-factor and CC from Molrep? If your R is sub-40% you have
probably got all the monomers.
You could also put the current model into your favourite refinement program
for a few cycles and see how things progress... RESOLVE when run with
prime-and-switch phasing can also be very good at revealing extra
info/monomers...
HTH,
Dave
On 6/12/05 3:16 pm, "Francisco J. Enguita" <[EMAIL PROTECTED]> thought:
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>
>
> Dear All :
>
> I got a pretty difficult case (I guess) of Molecular Replacement. My
> protein crystallize in a P21 spacegroup with cell dimensions of around
> 100 x 200 x 220 A. By Matthews analysis the ASU could accomodate from 16
> to 18 molecules of the protein (Molecular weight around 38 kDa). The
> resolution of the data is around 2.7 A.
>
> I have run Phaser and it found 10 molecules within the ASU, but the
> program failed to find more. I have made and NCS averaging with these
> molecules to build up a more precise model, and tried again Phaser with
> the same results. I have also tried Molrep with the same results.
>
> Does anybody experienced a problem like this ?. Any suggestion of
> strategies to find the rest of the molecules that will complete the
> ASU ?.
>
> Any help will be sincerely appreciated.
>
> Cheers
>
> Francisco
>
>
>
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