title: RPA nucleic acid-binding properties of IFI16-HIN200.
abstract: InterFeron-gamma Inducible protein 16 (IFI16) belongs to the interferon inducible HIN200 protein family that contains transcriptional regulators linked to cell cycle regulation and differentiation. All family members contain at most two domains of 200 amino acids, called HIN200, each containing two Oligonucleotide/Oligosaccharide Binding (OB) folds. IFI16 is involved in transcriptional repression and is a component of the DNA repair multi-protein complex known as BASC, which forms after UV-induced DNA damage. In this study, we used fold recognition and biophysical approaches as a tool to infer and validate functions to the HIN200 domain. Since the best template to model IFI16-HIN200 is Replication Protein A (RPA) in complex with single-stranded nucleic acids, we tested six RPA nucleic acid-binding characteristics for IFI16-HIN200. Our results indicate that IFI16-HIN200 is an RPA-like, OB-fold, nucleic acid-binding protein that binds to ssDNA with higher affinity than to dsDNA, recognizes ssDNA in the same orientation as RPA, oligomerizes upon ssDNA binding, wraps and stretches ssDNA, but does not destabilize dsDNA. We finally propose a framework model explaining how the HIN200 domain could prevent ssDNA from re-annealing.
authors.affiliation: Department of Molecular Biology and Biochemistry, Simon Fraser University, 8888 University Drive, Burnaby, British Columbia, Canada V5A 1S6.
authors.forename: Hongyue
authors.initials: H
authors.lastname: Yan
authors.forename: Kush
authors.initials: K
authors.lastname: Dalal
authors.forename: Benjamin K
authors.initials: BK
authors.lastname: Hon
authors.forename: Philippe
authors.initials: P
authors.lastname: Youkharibache
authors.forename: Desmond
authors.initials: D
authors.lastname: Lau
authors.forename: Frederic
authors.initials: F
authors.lastname: Pio
mesh_terms: D001483:Base Sequence; D001704:Biopolymers / Q000737:chemistry / Q000378:metabolism; D003001:Cloning, Molecular; D017931:DNA Primers; D004268:DNA-Binding Proteins / Q000378:metabolism*; D031541:Fluorescence Resonance Energy Transfer; D006801:Humans; D016297:Mutagenesis, Site-Directed; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D010750:Phosphoproteins / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding
chemical_list: D001704:Biopolymers; D017931:DNA Primers; D004268:DNA-Binding Proteins; C101635:HIN-200 protein, human; D009687:Nuclear Proteins; D010750:Phosphoproteins; C076700:IFI16 protein, human