Controlled rotation mechanism of DNA strand exchange by the Hin serine recombinase
Autor: | Xianbin Lei, Meghan M. McLean, Botao Xiao, John F. Marko, Reid C. Johnson |
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Jazyk: | angličtina |
Rok vydání: | 2016 |
Předmět: |
0301 basic medicine
Models Molecular Rotation Protein Conformation Chemical Biology Article law.invention Serine 03 medical and health sciences chemistry.chemical_compound Bacterial Proteins Genetic law Salmonella Models Factor For Inversion Stimulation Protein Genetics Recombinase Point Mutation Site-specific recombination DNA Nucleotidyltransferases chemistry.chemical_classification Recombination Genetic DNA ligase Multidisciplinary Models Genetic DNA Superhelical Molecular DNA Recombinant Proteins Recombination DNA-Binding Proteins Protein Subunits 030104 developmental biology chemistry Biochemistry Models Chemical Recombinant DNA Biophysics Nucleic Acid Conformation Superhelical Plasmids |
Zdroj: | Scientific reports, vol 6, iss 1 Scientific Reports |
ISSN: | 2045-2322 |
DOI: | 10.1038/srep23697 |
Popis: | DNA strand exchange by serine recombinases has been proposed to occur by a large-scale rotation of halves of the recombinase tetramer. Here we provide the first direct physical evidence for the subunit rotation mechanism for the Hin serine invertase. Single-DNA looping assays using an activated mutant (Hin-H107Y) reveal specific synapses between two hix sites. Two-DNA “braiding” experiments, where separate DNA molecules carrying a single hix are interwound, show that Hin-H107Y cleaves both hix sites and mediates multi-step rotational relaxation of the interwinding. The variable numbers of rotations in the DNA braid experiments are in accord with data from bulk experiments that follow DNA topological changes accompanying recombination by the hyperactive enzyme. The relatively slow Hin rotation rates, combined with pauses, indicate considerable rotary friction between synapsed subunit pairs. A rotational pausing mechanism intrinsic to serine recombinases is likely to be crucial for DNA ligation and for preventing deleterious DNA rearrangements. |
Databáze: | OpenAIRE |
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