From: Lorenzo Casalino (
Date: Mon Jun 04 2018 - 21:38:37 CDT

Dear VMD users,

I have a protein embedded in a membrane which is upside down and I would like to flip it, possibly around its geometrical center, such that it assumes its correct orientation.
Importantly, the first, second and third principal axes of this protein are not aligned to the x,y,z axes and I don’t want them to be aligned.

Do you have any suggestion for doing this?

I have tried to play around with the orient package but I was only able to do this operation while also aligning the principal axes to the x,y,z axes (which I don’t want), using this:
  package require Orient
  namespace import Orient::orient
  set sel [atomselect top "all"]
  set I [draw principalaxes $sel]
  set A [orient $sel [lindex $I 2] {0 0 -1}]
  $sel move $A
  set I [draw principalaxes $sel]
  set A [orient $sel [lindex $I 1] {0 -1 0}]
  $sel move $A
  set I [draw principalaxes $sel]
Thank you,
Best regards