Monovalent cations use multiple mechanisms to resolve ribozyme misfolding.
Recent efforts have been made to unravel the independent roles of monovalent cations in RNA folding, primarily using the Tetrahymena ribozyme as a model. Here we report how monovalent cations impact the folding of the Candida ribozyme. Interestingly, this ribozyme requires an order of magnitude less monovalent cations (Na+ and Tris+) to commit to a new folding starting state in which the J3/4:P6 base triple is partially formed and mispairing in the L2.1 and L6 terminal loops is resolved. When Mg2+-induced ribozyme folding proceeded on the same energy landscape, the altered starting state led to a rapid assembly of the correct ribozyme core and a fivefold to 10-fold increase in the ribozyme activity. Moreover, when the ribozyme folding was started from a misfolding-prone state, high millimolar concentrations of monovalent cations moderately elevated the ribozyme activity by efficiently resolving the misfolding of a peripheral element, P5abc.
State Key Laboratory of Virology and Department of Biotechnology, College of Life Sciences, Wuhan University, Wuhan, Hubei 430072, PR China.
Yan-Fei
YF
Jiang
Mu
M
Xiao
Ping
P
Yin
Yi
Y
Zhang
D002175:Candida / Q000201:enzymology / Q000235:genetics; D002384:Catalysis; D002414:Cations, Monovalent; D008274:Magnesium / Q000378:metabolism; D017510:Protein Folding; D016337:RNA, Catalytic / Q000378:metabolism*; D012964:Sodium / Q000378:metabolism
D002414:Cations, Monovalent; D016337:RNA, Catalytic; D012964:Sodium; D008274:Magnesium