Abstract

A diverse group of DNA‐binding regulatory proteins share a common structural domain which is homologous to the sequence of a highly conserved and abundant chromosomal protein, HMG‐1. Proteins containing this HMG‐1 box regulate various cellular functions involving DNA binding, suggesting that the target DNA sequences share a common structural element. Members of this protein family exhibit a dual DNA‐binding specificity: each recognizes a unique sequence as well as a common DNA conformation. The highly conserved HMG‐1/‐2 proteins may modulate the binding of other HMG‐1 box proteins to bent DNA. We examine the structural and functional relationships between the proteins, identify their signature† and describe common features of their target DNA elements.