Chromomycin A3

Chromomycin A3 (CMA3) or Toyomycin is an anthraquinone antibiotic glycoside produced by the fermentation of a certain strain of Streptomyces griseus (No. 7). Chromomycin A3 (CMA3) or Toyomycin is an anthraquinone antibiotic glycoside produced by the fermentation of a certain strain of Streptomyces griseus (No. 7). In the presence of Mg2+ ions, Chromomycin A3 binds reversibly to DNA, preferentially to contiguous G/C base pairs. When bound to DNA, Chromomycin A3 has a maximum excitation wavelength of 445 nm (blue), and a maximum emission wavelength of 575 nm (yellow).