EUKARYOTIC DNA TOPOISOMERASE II-BETA

Type II DNA topoisomerase activity is required to change DNA topology. It is important in the relaxation of DNA supercoils generated by cell ular processes, such as transcription and replication, and it is essen tial for the condensation of chromosomes and their segregation during mitosis, In mammals this activity is derived from at least two isoform s, termed DNA topoisomerase II alpha and beta. The alpha isoform is in volved in chromosome condensation and segregation, whereas the role of the beta isoform is not yet clear. DNA topoisomerase II beta was firs t reported in 1987, Here we review the research on DNA topoisomerase I I beta over the last 10 years. BioEssays 20: 215-226, 1998. (C) 1998 J ohn Wiley & Sons, Inc.