DNA G-Quadruplex Recognition In Vitro and in Live Cells by a Structure-Specific Nanobody
Silvia Galli, Larry Melidis, Sean M. Flynn, Dhaval Varshney, Angela Simeone, Jochen Spiegel, Sarah K. Madden, David Tannahill, Shankar Balasubramanian
Abstract
measurements of SG4 mutants, including arginine-to-alanine point mutations that dramatically diminish G4 binding affinity. Importantly, predicted amino acid-G4 interactions were subsequently confirmed experimentally by biophysical measurements. We demonstrate that the nanobody can be expressed intracellularly and used to image endogenous G4 structures in live cells. We also use the SG4 protein to positionally map G4s in situ and also on fixed chromatin. SG4 is a valuable, new tool for G4 detection and mapping in cells.
Topics & Concepts
ChemistryDNAChromatinIn vitroAlanine scanningMutantGenomeComputational biologyMolecular biologyG-quadruplexCell biologyTranscription (linguistics)BiochemistryGeneBiologyMutagenesisPhilosophyLinguisticsDNA and Nucleic Acid ChemistryAdvanced biosensing and bioanalysis techniquesMonoclonal and Polyclonal Antibodies Research