RRC ID 30356
Author Kobayashi T, Takahara M, Miyagishima SY, Kuroiwa H, Sasaki N, Ohta N, Matsuzaki M, Kuroiwa T.
Title Detection and localization of a chloroplast-encoded HU-like protein that organizes chloroplast nucleoids.
Journal Plant Cell
Abstract Chloroplast DNA (cpDNA) is packed into discrete structures called chloroplast nucleoids (cp-nucleoids). The structure of cpDNA is thought to be important for its maintenance and regulation. In bacteria and mitochondria, histone-like proteins (such as HU and Abf2, respectively) are abundant and play important roles in DNA organization. However, a primary structural protein has yet to be found in cp-nucleoids. Here, we identified an abundant DNA binding protein from isolated cp-nucleoids of the primitive red alga Cyanidioschyzon merolae. The purified protein had sequence homology with the bacterial histone-like protein HU, and it complemented HU-lacking Escherichia coli mutants. The protein, called HC (histone-like protein of chloroplast), was encoded by a single gene (CmhupA) in the C. merolae chloroplast genome. Using immunofluorescence and immunoelectron microscopy, we demonstrated that HC was distributed uniformly throughout the entire cp-nucleoid. The protein was expressed constitutively throughout the cell and the chloroplast division cycle, and it was able to condense DNA. These results indicate that HC, a bacteria-derived histone-like protein, primarily organizes cpDNA into the nucleoid.
Volume 14(7)
Pages 1579-89
Published 2002-7-1
DOI 10.1105/tpc.002717
PMID 12119376
PMC PMC150708
MeSH Algal Proteins / genetics Algal Proteins / metabolism* Amino Acid Sequence Bacterial Proteins / genetics Chloroplasts / metabolism* DNA, Chloroplast / genetics* DNA-Binding Proteins / genetics DNA-Binding Proteins / metabolism Escherichia coli / genetics Genetic Complementation Test Immunoblotting Molecular Sequence Data Mutation Rhodophyta / genetics* Rhodophyta / metabolism Saccharomyces cerevisiae Proteins* Sequence Homology, Amino Acid Transcription Factors / genetics Transcription Factors / metabolism
IF 9.618
Times Cited 54
Algae NIES-3377