title: Barrier-to-autointegration factor (BAF) condenses DNA by looping.
abstract: Barrier-to-autointegration factor (BAF) is a protein that has been proposed to compact retroviral DNA, making it inaccessible as a target for self-destructive integration into itself (autointegration). BAF also plays an important role in nuclear organization. We studied the mechanism of DNA condensation by BAF using total internal reflection fluorescence microscopy. We found that BAF compacts DNA by a looping mechanism. Dissociation of BAF from DNA occurs with multiphasic kinetics; an initial fast phase is followed by a much slower dissociation phase. The mechanistic basis of the broad timescale of dissociation is discussed. This behavior mimics the dissociation of BAF from retroviral DNA within preintegration complexes as monitored by functional assays. Thus the DNA binding properties of BAF may alone be sufficient to account for its association with the preintegration complex.
authors.affiliation: Laboratory of Molecular Biology, Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA.
authors.forename: Dunja
authors.initials: D
authors.lastname: Skoko
authors.forename: Min
authors.initials: M
authors.lastname: Li
authors.forename: Ying
authors.initials: Y
authors.lastname: Huang
authors.forename: Michiyo
authors.initials: M
authors.lastname: Mizuuchi
authors.forename: Mengli
authors.initials: M
authors.lastname: Cai
authors.forename: Christina M
authors.initials: CM
authors.lastname: Bradley
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Pease
authors.forename: Botao
authors.initials: B
authors.lastname: Xiao
authors.forename: John F
authors.initials: JF
authors.lastname: Marko
authors.forename: Robert
authors.initials: R
authors.lastname: Craigie
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Mizuuchi
mesh_terms: D001665:Binding Sites; D002352:Carrier Proteins; D018360:Crystallography, X-Ray; D004247:DNA / Q000737:chemistry* / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000737:chemistry* / Q000378:metabolism; D019281:Dimerization; D006801:Humans; D008856:Microscopy, Fluorescence; D011487:Protein Conformation; D017510:Protein Folding
chemical_list: D002352:Carrier Proteins; D004268:DNA-Binding Proteins; D004247:DNA