Identification of two mismatch-binding activities in protein extracts of Schizosaccharomyces pombe.
We have performed band-shift assays to identify mismatch-binding proteins in cell extracts of Schizosaccharomyces pombe. By testing heteroduplex DNA containing either a T/G or a C/C mismatch, two distinct band shifts were produced in the gels. A low mobility complex was observed with the T/G substrate, while a high mobility complex was present with C/C. Further analysis of the mismatch-binding specificities revealed that the T/G binding activity also binds to T/C, C/T, T/T, T/-, A/-, C/-, G/-, G/G, A/A, A/C, A/G, G/T, G/A, and C/A substrates with varying efficiencies, but not binds to C/C. The C/C binding activity efficiently binds to C/C, T/C, C/T, C/A, A/C, C/-, and weakly also to T/T, while all other mispairs are not recognized. Protein extracts of a mutant strain, defective in the mutS homologue swi4, displayed both mismatch-binding activities. Thus, swi4 does not encode for either one of the mismatch-binding proteins.
Fleck
O
O
Institute of General Microbiology, University of Bern, Switzerland.
Schär
P
P
Kohli
J
J
D001483:Base Sequence; D004271:DNA, Fungal / Q000378:metabolism*; D004277:DNA, Single-Stranded / Q000138:chemical synthesis / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism*; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D009154:Mutation; D009692:Nucleic Acid Heteroduplexes / Q000378:metabolism*; D011089:Polydeoxyribonucleotides / Q000138:chemical synthesis / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins; D012568:Schizosaccharomyces / Q000378:metabolism*; D014157:Transcription Factors
D004271:DNA, Fungal; D004277:DNA, Single-Stranded; D004268:DNA-Binding Proteins; D005656:Fungal Proteins; D009692:Nucleic Acid Heteroduplexes; D011089:Polydeoxyribonucleotides; C062214:SWI4 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors