FS23 binds to the N-terminal domain of human Hsp90：A novel small inhibitor for Hsp90

The N-terminal domain of heat shock protein 90(Hsp90~N) is responsible for the catalytic activity of Hsp90.The reported inhibitors of Hsp90 bind to this domain and would inhibit tumor growth and progression. Here,we synthesized FS23, a small molecule inhibitor of hsp90 and collected X-ray diffraction data of the complex crystal of Hsp90-FS23. High resolution X-ray crystallography shows that FS23 interacted with Hsp90 Nat the nucleotide binding cleft, and this suggests that FS23 may complete with nucleotides to bind to Hsp90~N. The crystal structure and the interaction between Hsp90 Nand FS23 suggest a rational basis for the design of novel antitumor drugs.