The recombination directionality factor, Xis, is a DNA bending protein that determines the outcome of integrase-mediated site-specific recombination by redesign of higher-order protein-DNA architectures. Although the attachment site DNA of mycobacteriophage Pukovnik is likely to contain four sites for Xis binding, Xis crystals contain five subunits in the asymmetric unit, four of which align into a Xis filament and a fifth that is generated by an unusual domain swap. Extensive intersubunit contacts stabilize a bent filament-like arrangement with Xis monomers aligned head to tail. The structure implies a DNA bend of ~120°, which is in agreement with DNA bending measured in vitro. Formation of attR-containing intasomes requires only Int and Xis, distinguishing Pukovnik from lambda. Therefore, we conclude that, in Pukovnik, Xis-induced DNA bending is sufficient to promote intramolecular Int-mediated bridges during intasome formation.
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http://dx.doi.org/10.1016/j.jmb.2013.10.002 | DOI Listing |
Nucleic Acids Res
January 2025
Department of Molecular Biology, Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka 812-8582, Japan.
Oscillation of the active form of the initiator protein DnaA (ATP-DnaA) allows for the timely regulation for chromosome replication. After initiation, DnaA-bound ATP is hydrolyzed, producing inactive ADP-DnaA. For the next round of initiation, ADP-DnaA interacts with the chromosomal locus DARS2 bearing binding sites for DnaA, a DNA-bending protein IHF, and a transcription activator Fis.
View Article and Find Full Text PDFConnections between the mechanical properties of DNA and biological functions have been speculative due to the lack of methods to measure or predict DNA mechanics at scale. Recently, a proxy for DNA mechanics, cyclizability, was measured by loop-seq and enabled genome-scale investigation of DNA mechanics. Here, we use this dataset to build a computational model predicting bias-corrected intrinsic cyclizability, with near-perfect accuracy, solely based on DNA sequence.
View Article and Find Full Text PDFComput Biol Chem
December 2024
Faculty of Biochemistry and Molecular Medicine, University of Oulu, PO Box 5400, Oulu 90014, Finland; Biocenter Oulu, University of Oulu, PO Box 5400, Oulu 90014, Finland. Electronic address:
Single-stranded breaks (SSBs) are the most frequent DNA lesions threatening genomic integrity-understanding how DNA sensor proteins recognize certain SSB types is crucial for studies of the DNA repair pathways. During repair of damaged DNA the final SSB that is to be ligated contains a 5'-phosphorylated end. The present work employed molecular simulation (MD) of DNA with a phosphorylated break in solution to address multiple questions regarding the dynamics of the break site.
View Article and Find Full Text PDFBiosensors (Basel)
December 2024
Department of Biomedical-Chemical Engineering, The Catholic University of Korea, Bucheon 14662, Republic of Korea.
In the biosensor field, the accurate detection of contagious disease has become one of the most important research topics in the post-pandemic period. However, conventional contagious viral biosensors normally require chemical modifications to introduce the probe molecules to nucleic acids such as a redox indicator, fluorescent dye, or quencher for biosensing. To avoid this complex chemical modification, in this research, mismatched DNA with an intercalated metal ion complex (MIMIC) is employed as the probe sequence.
View Article and Find Full Text PDFACS Nano
December 2024
Department of Mechanical Engineering, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Korea.
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