Updated publication reference for PubMed record(s): 33579945. Proteins co-purifying with recombinantly purified and N-terminally GFP-3C-tagged CTCF N-terminus (amino acids 1-293) produced in bacteria were identified by incubating the tagged bait with soluble nuclear protein extracts from 0-12h hour-old wildtype (OregonR strain) Drosophila melanogaster embryos.