Abstract
Phytochromes are well-known photoreceptors mediating photomorphogenetic responses in plants. Plant phytochromes and bacteriophytochromes covalently bind a linear tetrapyrrole as a chromophore, and show red/far-red reversible photoconversion. PixJ1 is a phytochrome-like photoreceptor necessary for positive phototaxis in a unicellular cyanobacterium Synechocystis sp. PCC 6803. We have already reported that PixJ1 protein covalently bound a linear tetrapyrrole and showed a novel blue (λAmax= 435 nm)/green (λAmax= 535 nm) reversible photoconversion. We have already presented the interconvertible photoreactions of PixJ1 by low temperature light-induced UV-Vis difference spectroscopy analyses. In this study, light extinction wavelength and temperature conditions were improved and provided detailed schemes of photoreactive pathway of PixJ1. We will discuss the possible photoreactions of PixJ1.
