Rapid compaction during RNA folding.
We have used small angle x-ray scattering and computer simulations with a coarse-grained model to provide a time-resolved picture of the global folding process of the Tetrahymena group I RNA over a time window of more than five orders of magnitude. A substantial phase of compaction is observed on the low millisecond timescale, and the overall compaction and global shape changes are largely complete within one second, earlier than any known tertiary contacts are formed. This finding indicates that the RNA forms a nonspecifically collapsed intermediate and then searches for its tertiary contacts within a highly restricted subset of conformational space. The collapsed intermediate early in folding of this RNA is grossly akin to molten globule intermediates in protein folding.
Russell
Rick
R
Department of Biochemistry, Stanford University, Stanford, CA 94305, USA.
Millett
Ian S
IS
Tate
Mark W
MW
Kwok
Lisa W
LW
Nakatani
Bradley
B
Gruner
Sol M
SM
Mochrie
Simon G J
SG
Pande
Vijay
V
Doniach
Sebastian
S
Herschlag
Daniel
D
Pollack
Lois
L
D000818:Animals; D003198:Computer Simulation; D009690:Nucleic Acid Conformation; D016337:RNA, Catalytic / Q000737:chemistry*; D012542:Scattering, Radiation; D013768:Tetrahymena / Q000235:genetics*
D016337:RNA, Catalytic