1u3c
Crystal Structure of the PHR domain of Cryptochrome 1 from Arabidopsis thaliana
OverviewOverview
Signals generated by cryptochrome (CRY) blue-light photoreceptors are responsible for a variety of developmental and circadian responses in plants. The CRYs are also identified as circadian blue-light photoreceptors in Drosophila and components of the mammalian circadian clock. These flavoproteins all have an N-terminal domain that is similar to photolyase, and most have an additional C-terminal domain of variable length. We present here the crystal structure of the photolyase-like domain of CRY-1 from Arabidopsis thaliana. The structure reveals a fold that is very similar to photolyase, with a single molecule of FAD noncovalently bound to the protein. The surface features of the protein and the dissimilarity of a surface cavity to that of photolyase account for its lack of DNA-repair activity. Previous in vitro experiments established that the photolyase-like domain of CRY-1 can bind Mg.ATP, and we observe a single molecule of an ATP analog bound in the aforementioned surface cavity, near the bound FAD cofactor. The structure has implications for the signaling mechanism of CRY blue-light photoreceptors.
About this StructureAbout this Structure
1U3C is a Single protein structure of sequence from Arabidopsis thaliana. Full crystallographic information is available from OCA.
ReferenceReference
Structure of the photolyase-like domain of cryptochrome 1 from Arabidopsis thaliana., Brautigam CA, Smith BS, Ma Z, Palnitkar M, Tomchick DR, Machius M, Deisenhofer J, Proc Natl Acad Sci U S A. 2004 Aug 17;101(33):12142-7. Epub 2004 Aug 6. PMID:15299148 Page seeded by OCA on Sat May 3 10:42:40 2008