Regulation of the function of eukaryotic DNA topoisomerase I: analysis of the binding step and of the catalytic constants of topoisomerization as a function of DNA topology.

It was previously observed that two steps of the reaction of eukaryotic DNA topoisomerase I (topoisomerization and cleavage) depend upon the conformation of the DNA substrate: in both instances the supercoiled form is a more efficient substrate than the relaxed one. This paper reports the analysis of two other steps of the reaction: the binding of DNA topoisomerase I to DNA and the catalytic constants (Kcs) of topoisomerization as a function of the topology of the substrate. Binding. Competition assays show that supercoiled DNA binds the enzyme with even slower kinetics than the relaxed form. Therefore, the preferential topoisomerization of supercoiled DNA is not due to the binding step. Additional evidence that the rate-limiting step of the topoisomerization reaction is not the binding of the enzyme to DNA is provided by the fact that the kinetics of relaxation is first order. Catalysis. The Kcs of the topoisomerization reaction have been calculated and it was shown that they do not vary as a function of the topology of the substrate or of its size. Taken together, the data on binding, cleavage, topoisomerization, and Kcs suggest that the preferential topoisomerization of torsionally strained DNA is due to the higher availability, on this topological form, of DNA sites that allow the onset of the reaction.

[1]  U. Mortensen,et al.  Interactions between eukaryotic DNA topoisomerase I and a specific binding sequence. , 1989, The Journal of biological chemistry.

[2]  G. Costanzo,et al.  Linkage reduction allows reconstitution of nucleosomes on DNA microdomains. , 1989, Journal of molecular biology.

[3]  E. Di Mauro,et al.  Regulation of the function of eukaryotic DNA topoisomerase I: topological conditions for inactivity. , 1989, Proceedings of the National Academy of Sciences of the United States of America.

[4]  E. Di Mauro,et al.  DNA conformational variations in the in vitro torsionally strained Ig kappa light chain gene localize on consensus sequences. , 1988, Biochimica et biophysica acta.

[5]  E. Di Mauro,et al.  Eukaryotic DNA topoisomerase I reaction is topology dependent. , 1988, Nucleic acids research.

[6]  J. Wang,et al.  Involvement of DNA topoisomerase I in transcription of human ribosomal RNA genes. , 1988, Proceedings of the National Academy of Sciences of the United States of America.

[7]  J. Wang,et al.  Supercoiling of the DNA template during transcription. , 1987, Proceedings of the National Academy of Sciences of the United States of America.

[8]  G. Schütz,et al.  Camptothecin-induced in vivo topoisomerase I cleavages in the transcriptionally active tyrosine aminotransferase gene , 1987, Cell.

[9]  S. Elgin,et al.  Localization of specific topoisomerase I interactions within the transcribed region of active heat shock genes by using the inhibitor camptothecin , 1987, Molecular and cellular biology.

[10]  R. Sternglanz,et al.  Need for DNA topoisomerase activity as a swivel for DNA replication for transcription of ribosomal RNA , 1987, Nature.

[11]  O. Westergaard,et al.  A high affinity topoisomerase I binding sequence is clustered at DNAase I hypersensitive sites in tetrahymena R-chromatin , 1985, Cell.

[12]  M. Muller.  Quantitation of eukaryotic topoisomerase I reactivity with DNA. Preferential cleavage of supercoiled DNA. , 1985, Biochimica et biophysica acta.

[13]  J. Wang,et al.  The purification and characterization of DNA topoisomerases I and II of the yeast Saccharomyces cerevisiae. , 1984, The Journal of biological chemistry.

[14]  R. Burgess,et al.  DNA strand breakage by wheat germ type 1 topoisomerase. , 1984, Biochimica et biophysica acta.

[15]  E. Schon,et al.  Conformation of promoter DNA: Fine mapping of S1-hypersensitive sites , 1983, Cell.

[16]  Michael E. Smith,et al.  DNA sequences of two yeast promoter-up mutants , 1983, Nature.

[17]  D. Russell,et al.  Nucleotide sequence of the yeast alcohol dehydrogenase II gene. , 1983, The Journal of biological chemistry.

[18]  L. Liu,et al.  Association of eukaryotic DNA topoisomerase I with nucleosomes and chromosomal proteins. , 1983, Nucleic acids research.

[19]  J. Hearst,et al.  Size of the unwound region of DNA in Escherichia coli RNA polymerase and calf thymus RNA polymerase II ternary complexes. , 1983, Cold Spring Harbor symposia on quantitative biology.

[20]  J. Champoux,et al.  Multiple forms of rat liver type I topoisomerase. , 1983, Methods in enzymology.

[21]  L. J. Peck,et al.  DNA supercoiling and its effects on DNA structure and function. , 1983, Cold Spring Harbor symposia on quantitative biology.

[22]  R. Perry,et al.  Functional significance and evolutionary development of the 5′-terminal regions of immunoglobulin variable-region genes , 1982, Cell.

[23]  M. Ellison,et al.  Purification and properties of type 1 topoisomerase from chicken erythrocytes: mechanism of eukaryotic topoisomerase action. , 1982, Biochemistry.

[24]  J V Maizel,et al.  The nucleotide sequence of a 5.5-kilobase DNA segment containing the mouse kappa immunoglobulin J and C region genes. , 1981, The Journal of biological chemistry.

[25]  J. Seidman,et al.  A mutant immunoglobulin light chain is formed by aberrant DNA- and RNA-splicing events , 1980, Nature.

[26]  M. Kuehl,et al.  RNA splicing generates a variant light chain from an aberrantly rearranged κ gene , 1980, Nature.

[27]  W. Keller.  Determination of the number of superhelical turns in simian virus 40 DNA by gel electrophoresis. , 1975, Proceedings of the National Academy of Sciences of the United States of America.