1. A Chlamydomonas protein that binds single-stranded G-strand telomere DNA
- Author
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M. L. Kable, Marie E. Petracek, Lisa M. C. Konkel, and Judith Berman
- Subjects
DNA, Complementary ,Genes, Protozoan ,Molecular Sequence Data ,Protozoan Proteins ,DNA, Single-Stranded ,Biology ,General Biochemistry, Genetics and Molecular Biology ,chemistry.chemical_compound ,GTP-Binding Proteins ,Complementary DNA ,Consensus Sequence ,Animals ,Amino Acid Sequence ,RNA, Messenger ,Cloning, Molecular ,Molecular Biology ,Plant Proteins ,Repetitive Sequences, Nucleic Acid ,Single-strand DNA-binding protein ,Telomere-binding protein ,Base Sequence ,Sequence Homology, Amino Acid ,General Immunology and Microbiology ,General Neuroscience ,Binding protein ,Chlamydomonas ,Nucleic acid sequence ,RNA ,Sequence Analysis, DNA ,DNA, Protozoan ,Telomere ,biology.organism_classification ,Molecular biology ,DNA-Binding Proteins ,Biochemistry ,chemistry ,Chlamydomonas reinhardtii ,RNA, Protozoan ,DNA ,Research Article - Abstract
We have identified a protein in Chlamydomonas reinhardtii cell extracts that specifically binds the single-stranded (ss) Chlamydomonas G-strand telomere sequence (TTTTAGGG)n. This protein, called G-strand binding protein (GBP), binds DNA with two or more ss TTTTAGGG repeats. A single polypeptide (M(r) 34 kDa) in Chlamydomonas extracts binds (TTTTAGGG)n, and a cDNA encoding this G-strand binding protein was identified by its expression of a G-strand binding activity. The cDNA (GBP1) sequence predicts a protein product (Gbp1p) that includes two domains with extensive homology to RNA recognition motifs (RRMs) and a region rich in glycine, alanine and arginine. Antibody raised against a peptide within Gbp1p reacted with both the 34 kDa polypeptide and bound G-strand DNA-protein complexes in gel retardation assays, indicating that GBP1 encodes GBP. Unlike vertebrate heteronuclear ribonucleoproteins, GBP does not bind the cognate telomere RNA sequence UUUUAGGG in gel retardation, North-Western or competition assays. Thus, GBP is a new type of candidate telomere binding protein that binds, in vitro, to ss G-strand telomere DNA, the primer for telomerase, and has domains that have homology to RNA binding domains in other proteins.
- Published
- 1994