|
ИСТИНА |
Войти в систему Регистрация |
Интеллектуальная Система Тематического Исследования НАукометрических данных |
||
ALLOSTERIC REGULATION OF A-tRNA BINDING TO A RIBOSOME REVEALED VIA MOLECULAR DYNAMICS SIMULATIONтезисы доклада
- Авторы: Макарова Т.М., Богданов Алексей Алексеевич
- Сборник: Сборник тезисов докладов "X Международной конференции молодых ученых по химии "Менделеев 2017"
- Тезисы
- Год издания: 2017
- Место издания: Санкт-Петербург
- Первая страница: 382
- Последняя страница: 382
- Аннотация: Allosteric interaction inside the ribosome is a proved but poorly understood fact. Molecular dynamics simulations method beeing theoretical, nevertheless, enables to observe effects on individual residues and functional groups level. This method was employed to investigate experimentally detected phenomena of allosteric connection in the ribosome. First, 23S rRNA mutations UU2492-3C and A2531U (or A2531C) are known to decrease A-tRNA affinity to the large subunit of the ribosome. MD simulations of systems with these mutations showed reproducible severe disturbances in a structure formed by CCA-end of A-tRNA and residues 2553-2556 of a tip of H92 of 23S rRNA, while in simulations of the wild ribosome this structure was stable during many tens of nanoseconds, providing very close proximity of peptidyl transferrase reaction actors. Then, a controversial issue of a negative influence of E-tRNA to affinity of the ribosome to A-tRNA was a subject of the computational investigation. Multiple simulations of the ribosome carrying E- and P- or P- and A-tRNAs revealed that presence of E- or A- tRNA leads after short period (40-80 ns) of optimization to different mutually exclusive states, where residue U2555 switched between stacking (or near-stacking) with U2554 in the PE-state or, in the AP-state, total distortion of this stack to provide embedding of the CCA-end into the tip of the helix in order to form a rigid structure fixing the amino group of the A-tRNA amino acid residue in the very vicinity of the nucleophilic center of a nascent peptide chain attached to P-tRNA. The structure of the H92 in the PE-state was similar to those appeared in the mutated systems which eventually ejected CCA-end of the A-tRNA. Simulation of potential coexistence of E-, P- and A-tRNAs displayed crutial distortions of both competitive tRNA binding sites, so that potential participants of peptide transfer could not approach each other enough close.
- Добавил в систему: Сумбатян Наталия Владимировна