Thanks all of you who promptly replied my question.
I should have been more precise. I was referring to the symmetry of the
tetrameric particle (point symmetry) at the molecular level not at the
atomic level. This question has arisen because I have collected some
SAXS data of my protein in solution and I don't have a molecular model
to superpose to the experimental envelop. Others experimental data, gel
filtration and NAT-PAGE, suggest a tetrameric particle. On the other
side, P1, P2, P222 and P4 experimental envelops are quite different. So,
I am not sure which symmetry to take. Considering the native state (no
ligands at all), 4 identical subunits and that the interface of
oligomarization have to be conserved, I would take P222 or P4. However,
I can be able to imagine such spacial arrangement without a 4-fold axis
at the molecular level. Indeed, even my P222 experimental envelop does
have a 4-fold axis.
I appreciate if you could add some more comments on this.
Thanks in advance,
Fred
On Wed, 28 Jul 2010 15:31:45 -0300
> Fred<[log in to unmask]> wrote:
>
>> Dear CCP4bb,
>> Could someone please, point me to some references about non-symmetric tetramers? If I have a tetramer composed by 4 identical subunits, it'll always have a P4 point group symmetry?
>> Thank in advance,
>> Tomb
>>
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