Using Genetically Encodable Self-Assembling Gd(III) Spin Labels To Make In-Cell Nanometric Distance Measurements.

摘要: Double electron-electron resonance (DEER) can be used to study the structure of a protein in its native cellular environment. Until now, this has required isolation, vitro labeling, and reintroduction back into cells. We describe completely biosynthetic approach that avoids these steps. It exploits genetically encodable lanthanide-binding tags (LBT) form self-assembling Gd(III) metal-based spin labels enables direct in-cell measurements. This is demonstrated using pair LBTs encoded one at each end 3-helix bundle expressed E. coli grown on -supplemented medium. DEER measurements directly cells produced readily detectable time traces from which distance between could determined. work first use biosynthetically metal-containing for non-disruptive structural