A plant gene encoding a Myb-like protein that binds telomeric GGTTTAG repeats in vitro.
A gene (AtTRP1) encoding a telomeric repeat-binding protein has been isolated from Arabidopsis thaliana. AtTRP1 is a single copy gene located on chromosome 5 of A. thaliana. The protein AtTRP1 encoded by this gene is not only homologous to the Myb DNA-binding motifs of other telomere-binding proteins but also is similar to several initiator-binding proteins in plants. Gel retardation assay revealed that the 115 residues on the C terminus of this protein, including the Myb motif, are sufficient for binding to the double-stranded plant telomeric sequence. The isolated DNA-binding domain of AtTRP1 recognizes each telomeric repeat centered on the sequence GGTTTAG. The almost full-length protein of AtTRP1 does not form any complex at all with the DNA fragments carrying four or fewer GGTTTAG repeats. However, it forms a complex with the sequence (GGTTTAG)(8) more efficiently than with the sequence (GGTTTAG)(5). These data suggest that the minimum length of a telomeric DNA for AtTRP1 binding consists of five GGTTTAG repeats and that the optimal AtTRP1 binding may require eight or more GGTTTAG repeats. It also implies that this protein AtTRP1 may bind in vivo primarily to the ends of plant chromosomes, which consist of long stretches of telomeric repeats.
Institute of Botany, Academia Sinica, Taipei 115, Taiwan.
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Chen
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Wang
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Ho
D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics*; D029681:Arabidopsis Proteins; D001483:Base Sequence; D001665:Binding Sites; D002352:Carrier Proteins / Q000737:chemistry / Q000235:genetics*; D002874:Chromosome Mapping; D003001:Cloning, Molecular; D018744:DNA, Plant / Q000737:chemistry / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000737:chemistry*; D017343:Genes, Plant; D006801:Humans; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics; D020598:Proto-Oncogene Proteins c-myb / Q000737:chemistry; D012091:Repetitive Sequences, Nucleic Acid; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D016615:Telomere / Q000737:chemistry / Q000378:metabolism*; D034501:Telomere-Binding Proteins
D029681:Arabidopsis Proteins; D002352:Carrier Proteins; D018744:DNA, Plant; D004268:DNA-Binding Proteins; D010940:Plant Proteins; D020598:Proto-Oncogene Proteins c-myb; C428203:TRP1 telomere repeat-binding protein, Arabidopsis; D034501:Telomere-Binding Proteins