QUANTITATIVE-ANALYSIS OF THE TRANSCRIPTION FACTOR AP2 BINDING TO DNA BY ATOMIC-FORCE MICROSCOPY

Atomic force microscopy (AFM) allows to study the molecular structure of biological macromolecules with nm to Angstrom resolutions without c rystallization. We show here the applicability of AFM in the quantitat ive analysis of the molecular mechanisms of DNA/protein interaction: ( i) Protein-binding sites can be mapped over a few kilobases of target DNA. (ii) Multimerization state of DNA-binding proteins can be determi ned simply by measuring the sizes of proteins bound to the DNA. These features are significant advantages over the capabilities provided by conventional techniques in biochemistry and molecular and structural b iology. (C) 1996 Academic Press, Inc.