Vaccinia virus encapsidates a novel topoisomerase with the properties of a eucaryotic type I enzyme. J Biol Chem 1987 Jul 05;262(19):9309-15
Date
07/05/1987Pubmed ID
3036853Scopus ID
2-s2.0-0023645150 (requires institutional sign-in at Scopus site) 75 CitationsAbstract
A DNA topoisomerase has been purified from vaccinia virus cores. The native enzyme is composed of a single subunit of 32,000 daltons. The enzyme relaxes both positively and negatively supercoiled DNA in the absence of an energy cofactor. Enzymatic activity is stimulated by magnesium ions and inhibited by ATP, and during relaxation the topoisomerase changes the linking number of the DNA substrate by steps of one. Trapping of the covalent DNA-enzyme intermediate has been achieved, and analysis of the cleavage of duplex DNA by the enzyme reveals that it makes a single-strand break and forms a covalent bond through the 3'-end of the broken strand. Enzymatic activity and formation of the trapped intermediate are inhibited by the drugs novobiocin, coumermycin A1, and berenil. The virally encapsidated enzyme has novel properties but most closely resembles a eucaryotic type I topoisomerase.
Author List
Shaffer R, Traktman PMESH terms used to index this publication - Major topics in bold
Adenosine TriphosphateAminocoumarins
Cells
Coumarins
DNA Topoisomerases, Type I
DNA, Superhelical
Diminazene
Eukaryotic Cells
Magnesium
Molecular Weight
Nalidixic Acid
Novobiocin
Vaccinia virus
