The DNA-binding properties of only a few ARID family members have been reported. Drosophila Dri and its murine ortholog Bright (ARID3A), as well as human MRF2 (ARID5B) all bind AT-rich sites selectively (3,4,6). However, human p270 (ARID1A), the closely related human protein ARID1B, and their apparent Drosophila and yeast counterparts, Osa and SWI1, all bind DNA without sequence specificity (9,11,12,20). A better understanding of the biological role of the ARID family will require a more thorough understanding of the distribution of sequence-specific DNA-binding properties among the individual members. We therefore undertook a survey designed to determine the DNA-binding properties of at least one member of each ARID subfamily.
