Ribosomal RNA Kink-turn motif - a flexible molecular hinge

RÁZGA, Filip, Naděžda ŠPAČKOVÁ, Kamila RÉBLOVÁ, Jaroslav KOČA, Neocles B. LEONTIS a Jiří ŠPONER. Ribosomal RNA Kink-turn motif - a flexible molecular hinge. In Conference on Current Trends in Computational Chemistry. prve. Jackson, MS, USA: Jackson, Miss, USA, 2004, s. 87-87.

Základní údaje

• Originální název: Ribosomal RNA Kink-turn motif - a flexible molecular hinge
• Název česky: Ribozomalny Kink-turn motiv - flexibilny molekularny klb
• Autoři: RÁZGA, Filip (703 Slovensko), Naděžda ŠPAČKOVÁ (203 Česká republika), Kamila RÉBLOVÁ (203 Česká republika), Jaroslav KOČA (203 Česká republika, garant), Neocles B. LEONTIS (840 Spojené státy) a Jiří ŠPONER (203 Česká republika).
• Vydání: prve. Jackson, MS, USA, Conference on Current Trends in Computational Chemistry, od s. 87-87, 1 s. 2004.
• Nakladatel: Jackson, Miss, USA

Další údaje

• Originální jazyk: angličtina
• Typ výsledku: Stať ve sborníku
• Obor: 10403 Physical chemistry
• Stát vydavatele: Spojené státy
• Utajení: není předmětem státního či obchodního tajemství
• Kód RIV: RIV/00216224:14310/04:00021349
• Organizační jednotka: Přírodovědecká fakulta
• UT WoS: 000223795600007
• Klíčová slova anglicky: Kink turn; RNA flexibility
• Štítky: Kink turn, RNA flexibility

Anotace

Ribosomal RNA K-turn motifs are asymmetric internal loops characterized by a sharp bend in the phosphodiester backbone resulting in "V" shaped structures, recurrently observed in ribosomes and showing high degree of sequence conservation. We have carried out extended explicit solvent molecular dynamics simulations of selected K-turns, in order to investigate their intrinsic structural and dynamical properties. The simulations reveal an unprecedented dynamical flexibility of the K-turns around their x-ray geometries. The K-turns sample, on the nanosecond timescale, different conformational substates. The overall behaviour of the simulations suggests that the sampled geometries are essentially isoenergetic and separated by minimal energy barriers. The nanosecond dynamics of isolated K-turns can be qualitatively considered as motion of two rigid helix stems controlled by a very flexible internal loop which then leads to substantial hinge-like motions between the two stems. This internal dynamics of K-turns is strikingly different for example from the bacterial 5S rRNA Loop E motif or BWYV frameshifting pseudoknot which appear to be rigid in the same type of simulations. Bistability and flexibility of K-turns was also suggested by several recent biochemical studies. Although the results of MD simulations should be considered as a qualitative picture of the K-turn dynamics due to force field and sampling limitations, the main advantage of the MD technique is it ability to investigate the region immediately around their ribosomal-like geometries. This part of the conformational space is not well characterised by the solution experiments due to large-scale conformational changes seen in the experiments. We suggest that K-turns are well suited to act as flexible structural elements of ribosomal RNA. They can for example be involved in mediation of large-scale motions or they can allow a smooth assembling of the other parts of the ribosome.

Anotace česky

Ribosomal RNA K-turn motifs are asymmetric internal loops characterized by a sharp bend in the phosphodiester backbone resulting in "V" shaped structures, recurrently observed in ribosomes and showing high degree of sequence conservation. We have carried out extended explicit solvent molecular dynamics simulations of selected K-turns, in order to investigate their intrinsic structural and dynamical properties. The simulations reveal an unprecedented dynamical flexibility of the K-turns around their x-ray geometries. The K-turns sample, on the nanosecond timescale, different conformational substates. The overall behaviour of the simulations suggests that the sampled geometries are essentially isoenergetic and separated by minimal energy barriers. The nanosecond dynamics of isolated K-turns can be qualitatively considered as motion of two rigid helix stems controlled by a very flexible internal loop which then leads to substantial hinge-like motions between the two stems. This internal dynamics of K-turns is strikingly different for example from the bacterial 5S rRNA Loop E motif or BWYV frameshifting pseudoknot which appear to be rigid in the same type of simulations. Bistability and flexibility of K-turns was also suggested by several recent biochemical studies. Although the results of MD simulations should be considered as a qualitative picture of the K-turn dynamics due to force field and sampling limitations, the main advantage of the MD technique is it ability to investigate the region immediately around their ribosomal-like geometries. This part of the conformational space is not well characterised by the solution experiments due to large-scale conformational changes seen in the experiments. We suggest that K-turns are well suited to act as flexible structural elements of ribosomal RNA. They can for example be involved in mediation of large-scale motions or they can allow a smooth assembling of the other parts of the ribosome.

Návaznosti

• LN00A016, projekt VaV: Název: BIOMOLEKULÁRNÍ CENTRUM

Investor: Ministerstvo školství, mládeže a tělovýchovy ČR, Biomolekulární centrum