Structure of the photoactive yellow protein reconstituted with caffeic acid at 1.16 A resolution.
van Aalten, D.M., Crielaard, W., Hellingwerf, K.J., Joshua-Tor, L.(2002) Acta Crystallogr D Biol Crystallogr 58: 585-590
- PubMed: 11914481 
- DOI: https://doi.org/10.1107/s0907444902001257
- Primary Citation of Related Structures:  
1KOU - PubMed Abstract: 
A structural study is described of the photoactive yellow protein (PYP) reconstituted with the chromophore derivative 3,4-dihydroxycinnamic acid. The crystal structure of PYP reconstituted with this chromophore at 1.16 A resolution is reported in space group P6(5). This is the first high-resolution structure of a photoreceptor containing a modified chromophore. The introduction of an extra hydroxyl group in the native chromophore (i.e. p-coumaric acid) appears to perturb the structure of the hybrid yellow protein only slightly. The chromophore is bound by the protein in two different conformations, separated by a rotation of 180 degrees of the catechol ring. In combination with available spectroscopic data, it is concluded that the caffeic acid chromophore binds to the protein in a strained conformation, which leads to a faster ejection from the chromophore-binding pocket upon pB formation.
Organizational Affiliation: 
W. M. Keck Structural Biology, Cold Spring Harbor Laboratory, 1 Bungtown Road, Cold Spring Harbor, NY 11724, USA.