Identification and characterization of three telomere repeat-binding factors in rice.
Telomeres consist of nucleoprotein complexes that protect chromosome end structures. Here, we describe three OsTRBF genes, encoding telomere repeat-binding factors of the single Myb histone family in rice. The predicted proteins contain a Myb DNA-binding motif and a linker histone H1/H5 domain in the N-terminal and central regions, respectively. The OsTRBF transcripts were constitutively detected in rice plants grown under greenhouse conditions. Gel retardation assays showed that these OsTRBF proteins bind specifically to the plant double-stranded telomeric sequence, TTTAGGG, with markedly different binding affinities as judged by their respective dissociation constants. Yeast two-hybrid and in vitro pull-down assays indicated that both OsTRBF1 and OsTRBF2 interact with one another to form homo- and hetero-complexes, while OsTRBF3 appeared to act as a monomer. Our results suggest that OsTRBFs play combinatory roles in the function and structure of telomeres in rice.
Byun
Mi Young
MY
Department of Biology, College of Life Science and Biotechnology, Yonsei University, Seoul 120-749, Republic of Korea.
Hong
Jong-Pil
JP
Kim
Woo Taek
WT
D000595:Amino Acid Sequence; D019281:Dimerization; D024202:Electrophoretic Mobility Shift Assay; D008969:Molecular Sequence Data; D012275:Oryza / Q000235:genetics / Q000378:metabolism*; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D016615:Telomere / Q000378:metabolism*; D034501:Telomere-Binding Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D020798:Two-Hybrid System Techniques
D010940:Plant Proteins; D034501:Telomere-Binding Proteins