Abstract
Diatoms play an important role as a primary producer on eanth. Recently, whole genome sequences of two diatoms, Thalassiosira pseudonana and Phaeodactylum tricornutum, were published by Joint Genome Institute (http://www.jgi.doe.gov/ ). We have reported isolation and characterization of PS I complexes from a centric diatom, Chaetoceros gracilis. Here, we show a simpler method to prepare PS I complexes from C. gracilis and T. pseudonana as well. The thylakoids solubilized by n-dodecyl- β -D-maltoside (DDM) was diluted to decrease the DDM concentration and then centrifuged. The resulting pellet was resuspended, and PS I complexes were purified by anion exchange chromatography. This purified PS I complexes had a high electron transfer rate and had all the electron transport components, including menaquinone-4 as A1. We will also discuss characteristics of the fucoxanthin-chlorophyll-binding protein I tightly bound to the PS I core complexes.
