A novel suicide substrate for DNA topoisomerases and site-specific recombinases.

Autor: Burgin AB Jr; Laboratory of Molecular Biology, National Institute of Mental Health, Bethesda, MD 20892, USA., Huizenga BN, Nash HA
Jazyk: angličtina
Zdroj: Nucleic acids research [Nucleic Acids Res] 1995 Aug 11; Vol. 23 (15), pp. 2973-9.
DOI: 10.1093/nar/23.15.2973
Abstrakt: DNA topoisomerases and DNA site-specific recombinases are biologically important enzymes involved in a diverse set of cellular processes. We show that replacement of a phosphodiester linkage by a 5'-bridging phosphorothioate linkage creates an efficient suicide substrate for calf thymus topoisomerase I and lambda integrase protein (Int). Although the bridging phosphorothioate linkage is cleaved by these enzymes, the 5'-sulfhydryl which is generated is not competent for subsequent ligation reactions. We use the irreversibility of Int-promoted cleavage to explore conditions and factors that contribute to various steps of lambda integrative recombination. The phosphorothioate substrates offer advantages over conventional suicide substrates, may be potent tools for inhibition of the relevant cellular enzymes and represent a unique tool for the study of many other phosphoryl transfer reactions.
Databáze: MEDLINE