ABSTRACT
Two questions at the forefront of biophysical sciences are biological
sensing and energy conversion. Photoactive yellow protein is at
the crossing point of these two topics as it converts light energy
into a structural change in the process of biological light sensing.
This bacterial photosensor is an excellent model system to study
how a protein achieves such a function as it is relatively small
and very stable. Over the years crystallography, spectroscopy, and
multiscale modeling techniques have been applied to study the
first step in the signal transduction process that it catalyzes-
the ultrafast isomerization of the p-coumaric acid chromophore intrinsic to PYP. This has culminated in an ever-better understanding
of the mechanism of its isomerization and the role of the protein
in this process. Here we provide a review of the current state of
knowledge on this issue.
