1S4S: Reaction Intermediate In The Photocycle Of Pyp, Intermediate Occupied Between 100 Micro-seconds To 5 Milli-seconds

We determine the number of authentic reaction intermediates in the later stages of the photocycle of photoactive yellow protein at room temperature, their atomic structures, and a consistent set of chemical kinetic mechanisms, by analysis of a set of time-dependent difference electron density maps spanning the time range from 5 micros to 100 ms. The successful fit of exponentials to right singular vectors derived from a singular value decomposition of the difference maps demonstrates that a chemical kinetic mechanism holds and that structurally distinct intermediates exist. We identify two time-independent difference maps, from which we refine the structures of the corresponding intermediates. We thus demonstrate how structures associated with intermediate states can be extracted from the experimental, time-dependent crystallographic data. Stoichiometric and structural constraints allow the exclusion of one kinetic mechanism proposed for the photocycle but retain other plausible candidate kinetic mechanisms.
PDB ID: 1S4SDownload
MMDB ID: 27395
PDB Deposition Date: 2004/1/17
Updated in MMDB: 2017/11
Experimental Method:
x-ray diffraction
Resolution: 1.9  Å
Source Organism:
Similar Structures:
Biological Unit for 1S4S: monomeric; determined by author
Molecular Components in 1S4S
Label Count Molecule
Protein (1 molecule)
Photoactive Yellow Protein
Molecule annotation
Chemical (1 molecule)
* Click molecule labels to explore molecular sequence information.

Citing MMDB