Mutagenesis of the HMGB (high-mobility group B) protein Cmb1 (cytosine-mismatch binding 1) of Schizosaccharomyces pombe: effects on recognition of DNA mismatches and damage
| Autor: | Christophe Kunz, Karin Zurbriggen, Oliver Fleck |
|---|---|
| Rok vydání: | 2003 |
| Předmět: |
Guanine
Hot Temperature DNA Repair HMG-box Base Pair Mismatch DNA repair Mitosis Antineoplastic Agents Polymerase Chain Reaction Biochemistry Fungal Proteins Cytosine chemistry.chemical_compound Schizosaccharomyces DNA Fungal Molecular Biology DNA Primers chemistry.chemical_classification biology Mutagenesis High Mobility Group Proteins Cell Biology Blotting Northern biology.organism_classification Molecular biology Amino acid DNA-Binding Proteins chemistry Mutation Schizosaccharomyces pombe Mutagenesis Site-Directed DNA mismatch repair Schizosaccharomyces pombe Proteins Cisplatin DNA DNA Damage Research Article Nucleotide excision repair |
| Zdroj: | Biochemical Journal. 372:651-660 |
| ISSN: | 1470-8728 0264-6021 |
| Popis: | Cmb1 (cytosine-mismatch binding 1) is a high-mobility group (HMG) protein of Schizosaccharomyces pombe, which consists of 223 amino acids and has a single HMG domain at the C-terminal end. We have created several mutant and deletion forms of the Cmb1 protein and studied the effects on general DNA binding and specific binding to DNA mismatches and damaged DNA. Cmb1Δ41 (i.e. Cmb1 from which the 41 N-terminal amino acids have been deleted) bound specifically to cytosine-containing mismatches, to the cisplatin-induced intrastrand cross-links cis-GG and cis-AG and to an O6-methylguanine lesion. DNA binding was not affected when the 45 N-terminal amino acids were deleted, but was abolished in the absence of the 50 N-terminal amino acids, and was reduced when Cmb1 was truncated by between five and eleven C-terminal amino acids. Cmb1, both with and without the C-terminal truncations, retained its DNA binding affinity after heating at 95 °C. The cmb1 gene was induced when S. pombe cells were treated with cisplatin. Mitotic mutation rates were increased in a S. pombe cmb1 null mutant and in a cmb1-(1–212) mutant, which encodes a Cmb1 protein lacking the 11 C-terminal amino acids. We conclude that mutation avoidance by Cmb1 is distinct from Msh2-dependent mismatch repair, but related to nucleotide excision repair. |
| Databáze: | OpenAIRE |
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