Although the first studied ARID-containing proteins bind preferentially to AT-rich sites, this behavior does not appear to be an intrinsic feature of the domain. Most ARID family members have not been characterized with respect to their DNA-binding behavior, but it has become apparent that not all ARIDs conform to the pattern of binding AT-rich sequences. p270 is a human ARID-containing protein that is an integral member of SWI/SNF-related chromatin remodeling complexes (7–10). p270 contains a complete ARID consensus and binds DNA with an affinity similar to Dri, but is unable to select oligonucleotides of any preferred sequence from a random pool (9,11). Lack of sequence specificity has been shown independently for the ARID family member, Osa, the closest Drosophila counterpart of p270 (12).
