Dynamic Stereoselection of Peptide Helicates and Their Selective Labeling of DNA Replication Foci in Cells**

Although largely overlooked in peptide engineering, coordination chemistry offers a new set of interactions that opens unexplored design opportunities for developing complex molecular structures. In this context, we report artificial ligands fold into chiral helicates the presence labile metal ions such as FeII and CoII. Heterochiral ?-turn-promoting sequences encode stereoselective folding define physicochemical properties their corresponding complexes. Circular dichroism NMR spectroscopy combination with computational methods allowed us to identify determine structure two isochiral ??-helicates, folded topological isomers. Finally, addition in-vitro characterization selective binding DNA three-way junctions, cell-microscopy experiments demonstrated rhodamine-labeled helicate was internalized selectively stains replication factories functional cells.