Three-dimensional organization of a gene locus is important for its regulation, as recently demonstrated for the beta-globin locus. When actively expressed, the cis-regulatory elements of the beta-globin locus are in proximity in the nuclear space, forming a compartment termed the Active Chromatin Hub (ACH). However, it is unknown which proteins are involved in ACH formation. Here, we show that EKLF, an erythroid transcription factor required for adult beta-globin gene transcription, is also required for ACH formation. We conclude that transcription factors can play an essential role in the three-dimensional organization of gene loci.