With both catalytic and genetic functions, ribonucleic acid (RNA) is perhaps the most pluripotent chemical species in molecular biology, and its functions are intimately linked to its structure and dynamics. Computer simulations, and in particular atomistic molecular dynamics (MD), allow structural dynamics of biomolecular systems to be investigated with unprecedented temporal and spatial resolution. We here provide a comprehensive overview of the fast-developing field of MD simulations of RNA molecules. We begin with an in-depth, evaluatory coverage of the most fundamental methodological challenges that set the basis for the future development of the field, in particular, the current developments and inherent physical limitations of the atomistic force fields and the recent advances in a broad spectrum of enhanced sampling methods. We also survey the closely related field of coarse-grained modeling of RNA systems. After dealing with the methodological aspects, we provide an exhaustive overview of the available RNA simulation literature, ranging from studies of the smallest RNA oligonucleotides to investigations of the entire ribosome. Our review encompasses tetranucleotides, tetraloops, a number of small RNA motifs, A-helix RNA, kissing-loop complexes, the TAR RNA element, the decoding center and other important regions of the ribosome, as well as assorted others systems. Extended sections are devoted to RNA-ion interactions, ribozymes, riboswitches, and protein/RNA complexes. Our overview is written for as broad of an audience as possible, aiming to provide a much-needed interdisciplinary bridge between computation and experiment, together with a perspective on the future of the field.

• MeSH
• DNA chemie   MeSH
• katalýza MeSH
• konformace nukleové kyseliny * MeSH
• počítačová simulace MeSH
• RNA chemie   MeSH
• simulace molekulární dynamiky * MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Research Support, N.I.H., Extramural MeSH
• Názvy látek
• DNA MeSH
• RNA MeSH

The L1 stalk is a key mobile element of the large ribosomal subunit which interacts with tRNA during translocation. Here, we investigate the structure and mechanical properties of the rRNA H76/H75/H79 three-way junction at the base of the L1 stalk from four different prokaryotic organisms. We propose a coarse-grained elastic model and parameterize it using large-scale atomistic molecular dynamics simulations. Global properties of the junction are well described by a model in which the H76 helix is represented by a straight, isotropically flexible elastic rod, while the junction core is represented by an isotropically flexible spherical hinge. Both the core and the helix contribute substantially to the overall H76 bending fluctuations. The presence of wobble pairs in H76 does not induce any increased flexibility or anisotropy to the helix. The half-closed conformation of the L1 stalk seems to be accessible by thermal fluctuations of the junction itself, without any long-range allosteric effects. Bending fluctuations of H76 with a bulge introduced in it suggest a rationale for the precise position of the bulge in eukaryotes. Our elastic model can be generalized to other RNA junctions found in biological systems or in nanotechnology.

• MeSH
• biomechanika MeSH
• konformace nukleové kyseliny MeSH
• ribozomální proteiny chemie   MeSH
• RNA ribozomální 23S chemie   MeSH
• simulace molekulární dynamiky MeSH
• velké podjednotky ribozomu archebakteriální chemie   MeSH
• velké podjednotky ribozomu bakteriální chemie   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• ribosomal protein L1 MeSH Prohlížeč
• ribozomální proteiny MeSH
• RNA ribozomální 23S MeSH

We present extensive explicit solvent molecular dynamics analysis of three RNA three-way junctions (3WJs) from the large ribosomal subunit: the 3WJ formed by Helices 90-92 (H90-H92) of 23S rRNA; the 3WJ formed by H42-H44 organizing the GTPase associated center (GAC) of 23S rRNA; and the 3WJ of 5S rRNA. H92 near the peptidyl transferase center binds the 3'-CCA end of amino-acylated tRNA. The GAC binds protein factors and stimulates GTP hydrolysis driving protein synthesis. The 5S rRNA binds the central protuberance and A-site finger (ASF) involved in bridges with the 30S subunit. The simulations reveal that all three 3WJs possess significant anisotropic hinge-like flexibility between their stacked stems and dynamics within the compact regions of their adjacent stems. The A-site 3WJ dynamics may facilitate accommodation of tRNA, while the 5S 3WJ flexibility appears to be essential for coordinated movements of ASF and 5S rRNA. The GAC 3WJ may support large-scale dynamics of the L7/L12-stalk region. The simulations reveal that H42-H44 rRNA segments are not fully relaxed and in the X-ray structures they are bent towards the large subunit. The bending may be related to L10 binding and is distributed between the 3WJ and the H42-H97 contact.

• MeSH
• archeální RNA chemie   MeSH
• bakteriální RNA chemie   MeSH
• Escherichia coli genetika   MeSH
• fosfáty chemie   MeSH
• Haloarcula marismortui genetika   MeSH
• konformace nukleové kyseliny MeSH
• RNA ribozomální 23S chemie   MeSH
• RNA ribozomální 5S chemie   MeSH
• simulace molekulární dynamiky MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH
• Research Support, U.S. Gov't, Non-P.H.S. MeSH
• Názvy látek
• archeální RNA MeSH
• bakteriální RNA MeSH
• fosfáty MeSH
• RNA ribozomální 23S MeSH
• RNA ribozomální 5S MeSH

The glmS catalytic riboswitch is part of the 5'-untranslated region of mRNAs encoding glucosamine-6-phosphate (GlcN6P) synthetase (glmS) in numerous gram-positive bacteria. Binding of the cofactor GlcN6P induces site-specific self-cleavage of the RNA. However, the detailed reaction mechanism as well as the protonation state of the glmS reactive form still remains elusive. To probe the dominant protonation states of key active site residues, we carried out explicit solvent molecular dynamic simulations involving various protonation states of three crucial active site moieties observed in the available crystal structures: (i) guanine G40 (following the Thermoanaerobacter tengcongensis numbering), (ii) the GlcN6P amino/ammonium group, and (iii) the GlcN6P phosphate moiety. We found that a deprotonated G40(-) seems incompatible with the observed glmS active site architecture. Our data suggest that the canonical form of G40 plays a structural role by stabilizing an in-line attack conformation of the cleavage site A-1(2'-OH) nucleophile, rather than a more direct chemical role. In addition, we observe weakened cofactor binding upon protonation of the GlcN6P phosphate moiety, which explains the experimentally observed increase in K(m) with decreasing pH. Finally, we discuss a possible role of cofactor binding and its interaction with the G65 and G1 purines in structural stabilization of the A-1(2'-OH) in-line attack conformation. On the basis of the identified dominant protonation state of the reaction precursor, we propose a hypothesis of the self-cleavage mechanism in which A-1(2'-OH) is activated as a nucleophile by the G1(pro-R(p)) nonbridging oxygen of the scissile phosphate, whereas the ammonium group of GlcN6P acts as the general acid protonating the G1(O5') leaving group.

• MeSH
• glukosa-6-fosfát analogy a deriváty   metabolismus   MeSH
• glukosamin analogy a deriváty   metabolismus   MeSH
• glutaminfruktosa-6-fosfáttransaminasa (izomerizující) genetika   MeSH
• katalytická doména * MeSH
• koenzymy metabolismus   MeSH
• konformace nukleové kyseliny MeSH
• molekulární sekvence - údaje MeSH
• protony * MeSH
• RNA katalytická chemie   genetika   metabolismus   MeSH
• sekvence nukleotidů MeSH
• simulace molekulární dynamiky * MeSH
• Thermoanaerobacter enzymologie   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH
• Názvy látek
• glucosamine 6-phosphate MeSH Prohlížeč
• glukosa-6-fosfát MeSH
• glukosamin MeSH
• glutaminfruktosa-6-fosfáttransaminasa (izomerizující) MeSH
• koenzymy MeSH
• protony * MeSH
• RNA katalytická MeSH

Helix 38 (H38) of the large ribosomal subunit, with a length of 110 A, reaches the small subunit through intersubunit bridge B1a. Previous cryo-EM studies revealed that the tip of H38 moves by more than 10 A from the non-ratcheted to the ratcheted state of the ribosome while mutational studies implicated a key role of flexible H38 in attenuation of translocation and in dynamical signaling between ribosomal functional centers. We investigate a region including the elbow-shaped kink-turn (Kt-38) in the Haloarcula marismortui archaeal ribosome, and equivalently positioned elbows in three eubacterial species, located at the H38 base. We performed explicit solvent molecular dynamics simulations on the H38 elbows in all four species. They are formed by at first sight unrelated sequences resulting in diverse base interactions but built with the same overall topology, as shown by X-ray crystallography. The elbows display similar fluctuations and intrinsic flexibilities in simulations indicating that the eubacterial H38 elbows are structural and dynamical analogs of archaeal Kt-38. We suggest that this structural element plays a pivotal role in the large motions of H38 and may act as fulcrum for the abovementioned tip motion. The directional flexibility inferred from simulations correlates well with the cryo-EM results.

• MeSH
• chlorid draselný chemie   MeSH
• Deinococcus genetika   MeSH
• elektronová kryomikroskopie MeSH
• Escherichia coli genetika   MeSH
• Haloarcula marismortui genetika   MeSH
• konformace nukleové kyseliny MeSH
• RNA ribozomální 23S chemie   MeSH
• simulace molekulární dynamiky MeSH
• sodík chemie   MeSH
• Thermus thermophilus genetika   MeSH
• velké podjednotky ribozomu archebakteriální chemie   MeSH
• velké podjednotky ribozomu bakteriální chemie   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH
• Názvy látek
• chlorid draselný MeSH
• RNA ribozomální 23S MeSH
• sodík MeSH

Functional RNA molecules such as ribosomal RNAs frequently contain highly conserved internal loops with a 5'-UAA/5'-GAN (UAA/GAN) consensus sequence. The UAA/GAN internal loops adopt distinctive structure inconsistent with secondary structure predictions. The structure has a narrow major groove and forms a trans Hoogsteen/Sugar edge (tHS) A/G base pair followed by an unpaired stacked adenine, a trans Watson-Crick/Hoogsteen (tWH) U/A base pair and finally by a bulged nucleotide (N). The structure is further stabilized by a three-adenine stack and base-phosphate interaction. In the ribosome, the UAA/GAN internal loops are involved in extensive tertiary contacts, mainly as donors of A-minor interactions. Further, this sequence can adopt an alternative 2D/3D pattern stabilized by a four-adenine stack involved in a smaller number of tertiary interactions. The solution structure of an isolated UAA/GAA internal loop shows substantially rearranged base pairing with three consecutive non-Watson-Crick base pairs. Its A/U base pair adopts an incomplete cis Watson-Crick/Sugar edge (cWS) A/U conformation instead of the expected Watson-Crick arrangement. We performed 3.1 µs of explicit solvent molecular dynamics (MD) simulations of the X-ray and NMR UAA/GAN structures, supplemented by MM-PBSA free energy calculations, locally enhanced sampling (LES) runs, targeted MD (TMD) and nudged elastic band (NEB) analysis. We compared parm99 and parmbsc0 force fields and net-neutralizing Na(+) vs. excess salt KCl ion environments. Both force fields provide a similar description of the simulated structures, with the parmbsc0 leading to modest narrowing of the major groove. The excess salt simulations also cause a similar effect. While the NMR structure is entirely stable in simulations, the simulated X-ray structure shows considerable widening of the major groove, loss of base-phosphate interaction and other instabilities. The alternative X-ray geometry even undergoes conformational transition towards the solution 2D structure. Free energy calculations confirm that the X-ray arrangement is less stable than the solution structure. LES, TMD and NEB provide a rather consistent pathway for interconversion between the X-ray and NMR structures. In simulations, the incomplete cWS A/U base pair of the NMR structure is water mediated and alternates with the canonical A-U base pair, which is not indicated by the NMR data. Completion of full cWS A/U base pair is prevented by the overall internal loop arrangement. In summary, the simulations confirm that the UAA/GAN internal loop is a molecular switch RNA module that adopts its functional geometry upon specific tertiary contexts.

• Publikační typ
• časopisecké články MeSH