Jagadish Babu Dasari1, Bini Chhetri Soren1, Alessio Ottaviani1,2, Cinzia Tesauro1,3, Simona Marino1, Beatrice Messina1, Paola Fiorani1,2. 1. Department of Biology, University of Rome Tor Vergata, Via Della Ricerca Scientifica 1, 00133 Rome, Italy. 2. Institute of Translational Pharmacology, National Research Council, CNR, Via Del Fosso del Cavaliere 100, Rome 00133, Italy. 3. Present address: Department of Molecular Biology and Genetics, University of Aarhus, C.F MøllersAllè 3, 8000 Aarhus C, Denmark.
Abstract
BACKGROUND: DNA topoisomerases 1B are a class of ubiquitous enzyme that solves the topological problems associated with biological processes such as replication, transcription and recombination. Numerous sequence alignment of topoisomerase 1B from different species shows that the lengths of different domains as well as their amino acids sequences are quite different. In the present study a hybrid enzyme, generated by swapping the N-terminal of Plasmodium falciparum into the corresponding domain of the human, has been characterized. METHODS: The chimeric enzyme was generated using different sets of PCR. The in vitro characterization was carried out using different DNA substrate including radio-labelled oligonucleotides. RESULTS: The chimeric enzyme displayed slower relaxation activity, cleavage and re-ligation kinetics strongly perturbed when compared to the human enzyme. CONCLUSION: These results indicate that the N-terminal domain has a crucial role in modulating topoisomerase activity in different species.
BACKGROUND: DNA topoisomerases 1B are a class of ubiquitous enzyme that solves the topological problems associated with biological processes such as replication, transcription and recombination. Numerous sequence alignment of topoisomerase 1B from different species shows that the lengths of different domains as well as their amino acids sequences are quite different. In the present study a hybrid enzyme, generated by swapping the N-terminal of Plasmodium falciparum into the corresponding domain of the human, has been characterized. METHODS: The chimeric enzyme was generated using different sets of PCR. The in vitro characterization was carried out using different DNA substrate including radio-labelled oligonucleotides. RESULTS: The chimeric enzyme displayed slower relaxation activity, cleavage and re-ligation kinetics strongly perturbed when compared to the human enzyme. CONCLUSION: These results indicate that the N-terminal domain has a crucial role in modulating topoisomerase activity in different species.
Authors: James F Carey; Sharon J Schultz; Lisa Sisson; Thomas G Fazzio; James J Champoux Journal: Proc Natl Acad Sci U S A Date: 2003-04-23 Impact factor: 11.205