SYNTHESIS AND STRUCTURES OF ZN(C6H12OS2)(2)(CLO4)(2) AND ZN(C3H6NS2)(2)(C3H4N2) - MODEL COMPOUNDS FOR THE ZN SITES IN RNA-POLYMERASE

Model compounds for the Zn sites of the beta' and the beta subunits in RNA polymerase [1] were synthesized. Single crystal structures and X-ray absorbtion spectroscopy measurements for these two model complexes are reported. In Zn(C6H12OS2)(2)(ClO4)(2), the Zn is coordinated by four sulfur and two oxygen atoms. The average Zn-S bond length is 2.514 Angstrom and the Zn-O bond length is 2.089 Angstrom, which are similar to these bond distances reported for the Zn site in the beta' subunit of RNA polymerase. In Zn(C3H6NS2)(2)(C3H4N2), the Zn atom is coordinated by four sulfur atoms and one nitrogen atom of an imidazole group. The average of the Zn-S bond length is 2.469 Angstrom and the Zn-N bond length is 2.009 Angstrom, which are also similar to the Zn-S and Zn-N bonds in the beta subunits of RNA polymerase.