Chromosomal proteins of Physarum polycephalum with preferential affinity for the sequence, poly d(A-T).poly d(A-T).
We have identified two novel chromosomal proteins from Physarum polycephalum using a protein blotting DNA-binding assay. A fraction of these proteins was readily released from nuclei by solutions of moderate ionic strength (0.15 N-0.35 M NaCl) or mild nuclease treatment and appear associated with chromatin that is nucleosome-free. A significant proportion of these proteins, however, was not released from nuclei by solutions of high ionic strength (1.6 M NaCl) or treatment with excess nuclease. These results suggest that these chromosomal proteins are distributed between transcriptionally-competent and inert domains of chromatin. Both proteins preferentially and tenaciously bound duplex DNA, especially to the alternating B-DNA conformation displayed by the synthetic sequence, poly d(A-T).poly d(A-T).
Magor
K A
KA
Department of Biology, Dalhousie University, Halifax, Nova Scotia, Canada.
Wright
J M
JM
D000818:Animals; D015825:Chromosomes, Fungal / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000378:metabolism*; D009687:Nuclear Proteins / Q000378:metabolism*; D016839:Physarum polycephalum / Q000235:genetics*; D011067:Poly dA-dT / Q000378:metabolism*
D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; D011067:Poly dA-dT