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Updated: Jun 4, 2026

Single-Molecule Imaging of EWS-FLI1 Condensates Assembling on DNA
Published on: September 8, 2021
Nuclear protein LEDGF/p75 recognizes supercoiled DNA by a novel DNA-binding domain
Kimiko M Tsutsui1, Kuniaki Sano, Osamu Hosoya
1Department of Neurogenomics, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, 2-5-1 Shikata-cho, Kita-ku, Okayama, 700-8558, Japan.
Abstract:
Lens epithelium-derived growth factor (LEDGF) or p75 is a co-activator of general transcription and also involved in insertion of human immunodeficiency virus type I (HIV-1) cDNA into host cell genome, which occurs preferentially to active transcription units. These phenomena may share an underlying molecular mechanism in common. We report here that LEDGF/p75 binds negatively supercoiled DNA selectively over unconstrained DNA. We identified a novel DNA-binding domain in the protein and termed it 'supercoiled DNA-recognition domain' (SRD). Recombinant protein fragments containing SRD showed a preferential binding to supercoiled DNA in vitro. SRD harbors a characteristic cluster of lysine and glutamic/aspartic acid residues. A polypeptide mimicking the cluster (K(9)E(9)K(9)) also showed this specificity, suggesting that the cluster is an essential element for the supercoil recognition. eGFP-tagged LEDGF/p75 expressed in the nucleus distributed partially in transcriptionally active regions that were identified by immunostaining of methylated histone H3 (H3K4me3) or incorporation of Br-UTP. This pattern of localization was observed with SRD alone but abolished if the protein lacked SRD. Thus, these results imply that LEDGF/p75 guides its binding partners, including HIV-1 integrase, to the active transcription site through recognition of negative supercoils generated around it.
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