Abstract
HU is a major component of the bacterial nucleoid. HU-like protein is encoded in plastid genome in the cryptomonad alga Guillardia theta and red alga Cyanidioschyzon merolae. However there is no homolog in Arabidopsis thaliana. We found a sequence encoding an HU-like protein from C. reinhardtii EST database and suggested that C. reinhardtii has HU-like protein encoded in the nuclear genome.
DNA-blot analysis was performed with an EST sequence probe, and showed that this gene exists in single copy. RNA-blot analysis showed a strong signal in the log phase (especially late-log phase). In contrast, we detect a weak signal in the stationary phase. We prepared single-stranded DNA, double-stranded DNA, and single-stranded RNA to study the binding of this protein. Gel mobility shift assay revealed that this protein binds to these nucleotides with no specificity in contrast to Escherichia coli HU. We will examine the localization of this protein.
