The same crystal in the ground state (purple, on left) and the M state (pale yellow, on right)

The late M photocycle intermediate

 

Light-induced reversible bleaching of D96N crystals

Purple (BR state) D96N crystal   Purple (BR state) D96N crystal next to oil droplet
 

   Bleached (M state) D96N crystal after brief exposure to yellow light
 

Click here for a quicktime movie showing three cycles of

During the second bleaching cycle the crystal "hops" into the oil droplet.

Note: The file is large (28 MBytes).  During the first 11 seconds the microscope is being focused.  The sequence was recorded at beamline 7-1 at the Stanford Synchrotron Radiation Laboratory (SSRL).
 
 

The paper:

Structural Changes in Bacteriorhodopsin During Ion Transport at 2 Angstrom Resolution.
H Luecke, B Schobert, H-T Richter, JP Cartailler, JK Lanyi (1999) Science 286, 255-260.
 

The atomic models:

1c8r.pdb (released Oct 12, 1999): 1.8 Å light-adapted ground-state structure of the D96N single-site mutant, described in the 1999 Science paper.

1c8s.pdb (released Oct 12, 1999): 2.0 Å M photocycle-intermediate structure of the D96N single-site mutant, described in the 1999 Science paper.
 

A few related web pointers: