Junk DNA: goodbye!: RNA shapes and activity (Introduction)

by David Turell , Wednesday, July 22, 2015, 20:11 (3412 days ago) @ Balance_Maintained

RNA's are produced in about 85% of DNA, but the functions of these twisting and turning RNA's is just now being uncovered:-http://www.nature.com/news/a-cellular-puzzle-the-weird-and-wonderful-architecture-of-rna-1.18014?WT.ec_id=NATURE-20150723&spMailingID=49156958&spUserID=MjA1NjE2NDU5MwS2&spJobID=722865381&spReportId=NzIyODY1MzgxS0-" In November 2013, they and their teams became the first to describe the shapes of thousands of RNAs in a living cell — revealing a veritable sculpture garden of different forms in the weedy thale cress, Arabidopsis thaliana1. One month later, a group at the University of California, San Francisco, reported a comparable study of yeast and human cells2. The number of RNA structures they managed to resolve was “unprecedented”, says Alain Laederach, an RNA biologist at the University of North Carolina at Chapel Hill (UNC).-"Scientists' view of RNA has transformed over the past few decades. Once, most RNAs were thought to be relatively uninteresting pieces of limp spaghetti that ferried information between the molecules that mattered, DNA and protein. Now, biologists know that RNAs serve many other essential functions: they help with protein synthesis, control gene activity and modify other RNAs. At least 85% of the human genome is transcribed into RNA, and there is vigorous debate about what, if anything, it does. (my bold)-"But a key mystery has remained: its convoluted structures. Unlike DNA, which forms a predictable double helix, RNA comprises a single strand that folds up into elaborate loops, bulges, pseudo-knots, hammerheads, hairpins and other 3D motifs. These structures flip and twist between different forms, and are thought to be central to the operation of RNA, albeit in ways that are not yet known. “It's a big missing piece of the puzzle of understanding how RNAs work,” says Jonathan Weissman, a biophysicist and leader of the yeast and human RNA study.-"In the past few years, researchers have begun to get a toehold on the problem. Bevilacqua, Weissman and others have devised techniques that allow them to take snapshots of RNA configurations en masse inside cells — and found that the molecules often look nothing like what is seen when RNA folds under artificial conditions. The work is helping them to decipher some of the rules that govern RNA structure, which might be useful in understanding human variation and disease — and even in improving agricultural crops."