Lipid vesicles chaperone an encapsulated RNA aptamer

• Published in: Nature communications 2018-06, Vol.9 (1), p.2313-11, Article 2313
• Main Authors: Saha, Ranajay, Verbanic, Samuel, Chen, Irene A.
• Format: Article
• Language: English
• Subjects: 631/181/904; 631/45/500; 631/57; Aptamers; Aptamers, Nucleotide - chemistry; Artificial Cells - chemistry; Chaperones; Confinement; Conformation; Encapsulation; Evolution; Fatty acids; Fatty Acids - chemistry; Fatty Acids, Monounsaturated - chemistry; Fitness; Gene sequencing; Glycerol; Humanities and Social Sciences; Lipids; Lipids - chemistry; Liposomes - chemistry; Magnesium - chemistry; Malachite green; Models, Molecular; Molecular chains; Molecular Chaperones; multidisciplinary; Nucleic Acid Conformation; Polyethylene glycol; Prebiotics; Ribonucleic acid; RNA; Science; Science (multidisciplinary); Thermodynamics; Vesicles
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-018-04783-8

The organization of molecules into cells is believed to have been critical for the emergence of living systems. Early protocells likely consisted of RNA functioning inside vesicles made of simple lipids. However, little is known about how encapsulation would affect the activity and folding of RNA. Here we find that confinement of the malachite green RNA aptamer inside fatty acid vesicles increases binding affinity and locally stabilizes the bound conformation of the RNA. The vesicle effectively ‘chaperones’ the aptamer, consistent with an excluded volume mechanism due to confinement. Protocellular organization thereby leads to a direct benefit for the RNA. Coupled with previously described mechanisms by which encapsulated RNA aids membrane growth, this effect illustrates how the membrane and RNA might cooperate for mutual benefit. Encapsulation could thus increase RNA fitness and the likelihood that functional sequences would emerge during the origin of life. So far little is known about how encapsulation affects the activity and folding of RNA, which is of interest for understanding the origin of cellular life. Here the authors show that encapsulation of functional RNA in vesicles increases RNA activity and improves RNA folding through a biophysical confinement effect.