Abstract
Phototropin (phot) is a blue light photoreceptor in plants that mediates phototropism, chloroplast relocation, stomata opening and leaf expansion. A phot molecule has two photoreceptive domains, LOV1 and LOV2, in the N-terminal half and the C-terminal half forms Ser/The kinase. Phot kinase is activated by blue light, in which LOV2 act as a light-regulated inhibitory domain. However, little is know regarding the molecular mechanism of the photoregulation.
In order to understand the molecular basis of the photoregulation, binding of LOV domains to kinase domain was analyzed by a docking simulation technique. LOV2 was revealed to bind to the active site of kinase domain to form a stable complex, however, LOV1 was not. The results well agree with the reported role of LOV2 in the photoregulation. In addition, the effects of the introduction of amino acid mutations into the estimated interaction site of LOV2 domain will be reported.
