Re: [ccp4bb]: How to make a movie

[Edward Berry <eaberry@lbl.gov>]

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Jeff Taylor wrote:
> 
> I wrote a simple morphing program a while back.  You give it two pdb
> files (first and last) and the number of steps you would like and it
> writes out pdb files with linearly interpolated coordinates.

That sounds almost too simple. Are bond lengths/angles preserved during 
the morph? if a Histidine rotated 180* about CHI2, wouldn't the NE1 and 
CE2 atoms pass through each other on the way to their new positions?  
Do any morphing programs preserve bond lengths and angles during the 
morph? Perhaps one could express the structure in terms of dihedral 
angles and interpolate linearly between the starting and final values
for the dihedral angles. Still in the case of large-scale movements 
you might get one domain passing through another on the way to its 
final position, where in nature it makes a two-stage movement to go 
around.

ed