DNA topoisomerase activity DNA topoisomerase type I (single strand cut, ATP-independent) activity https://github.com/geneontology/go-ontology/issues/15575 https://github.com/geneontology/go-ontology/issues/30193 untwisting enzyme activity EC:5.6.2.1 omega-protein activity Reactome:R-HSA-9914922 Note that a further distinction, between type IA and type IB topoisomerases, is based on sequence or structural similarity between gene products that possess type I catalytic activity. molecular_function deoxyribonucleate topoisomerase swivelase activity topoisomerase Catalysis of a DNA topological transformation by transiently cleaving one DNA strand at a time to allow passage of another strand; changes the linking number by +1 per catalytic cycle. GO:0003917 type I topoisomerase activity MetaCyc:5.99.1.2-RXN nicking-closing enzyme activity type I DNA topoisomerase activity DNA topoisomerase I activity relaxing enzyme activity