[Bioperl-l] Calculating distances from PDB files

[Robinson, Peter]

Dear bioperlers,

I couldn't seem to find an answer to this anywhere, but forgive me if I should have...

I would like to filter a set of PDB files for a given tetrapeptide and then calculate the distance between the C_alpha(1) and C_alpha(4) atoms. I am relatively new to this, but I have been able to extract the sequence from PDB files using Bio::Structure modules. When I look with Data::Dumper, I am unable to identify anything that looks like positional information for the residues. Does anybody have an example script or any suggestions?

Thanks,

Peter