5v3f

Publication Abstract from PubMed

Genetically encoded fluorescent protein tags have revolutionized proteome studies, whereas the lack of intrinsically fluorescent RNAs has hindered transcriptome exploration. Among several RNA-fluorophore complexes that potentially address this problem, RNA Mango has an exceptionally high affinity for its thiazole orange (TO)-derived fluorophore, TO1-Biotin (Kd approximately 3 nM), and, in complex with related ligands, it is one of the most redshifted fluorescent macromolecular tags known. To elucidate how this small aptamer exhibits such properties, which make it well suited for studying low-copy cellular RNAs, we determined its 1.7-A-resolution co-crystal structure. Unexpectedly, the entire ligand, including TO, biotin and the linker connecting them, abuts one of the near-planar faces of the three-tiered G-quadruplex. The two heterocycles of TO are held in place by two loop adenines and form a 45 degrees angle with respect to each other. Minimizing this angle would increase quantum yield and further improve this tool for in vivo RNA visualization.

Structural basis for high-affinity fluorophore binding and activation by RNA Mango.,Trachman RJ 3rd, Demeshkina NA, Lau MWL, Panchapakesan SSS, Jeng SCY, Unrau PJ, Ferre-D'Amare AR Nat Chem Biol. 2017 Jul;13(7):807-813. doi: 10.1038/nchembio.2392. Epub 2017 May , 29. PMID:28553947^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.