PHYSICAL BASIS OF A PROTEIN-DNA RECOGNITION CODE

Can a stereochemical recognition code explain sequence-specific protei n-nucleic acid interactions? Whereas a code that is generally applicab le to DNA-binding proteins of all known structural families is unattai nable, the indications are that a code can describe at least some of t he interactions of classical zinc fingers with DNA. The crystal struct ures of related zinc finger-DNA complexes reveal a remarkable mode of interaction that sets the framework for this code, and recent biochemi cal studies have elucidated the intermolecular contacts (contingent on this framework) that result in specificity.