[Biopython] help for overwrite a pdb file

[Peter Cock]

On Thu, Oct 6, 2011 at 11:43 AM, Elisa sechi <elisa.sechi85 at hotmail.it> wrote:
>
> Hi! All !
> I'm contacting you in order to ask help about Biopython.
> I'm using python,I have extract the atoms coordinates  of a protein from a pdb file and I have used quaternion in order to rotate the coordinates.
> I have put its in a new matrix but now the problem is: how do I save the cartesian coordinates in a pdb file???Do I have to create a new structure with the use of builder structure Class??
> I ask you if there is a way to overwrite the new cartesian coordinates in the old pdb file that i have used.
> Please help me!!!
> Thank you very much!
> Elisa
>   bye

There's an example here which rotates models in a PDB file and saves the output:
http://www.warwick.ac.uk/go/peter_cock/python/protein_superposition/

It is not using quaternions for the rotation, but otherwise it should
be helpful.

Peter