کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
2030786 1071249 2006 9 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
The Open State Gating Mechanism of Gramicidin A Requires Relative Opposed Monomer Rotation and Simultaneous Lateral Displacement
موضوعات مرتبط
علوم زیستی و بیوفناوری بیوشیمی، ژنتیک و زیست شناسی مولکولی زیست شیمی
پیش نمایش صفحه اول مقاله
The Open State Gating Mechanism of Gramicidin A Requires Relative Opposed Monomer Rotation and Simultaneous Lateral Displacement
چکیده انگلیسی

SummaryThe gating mechanism of the open state of the gramicidin A (gA) channel is studied by using a new Monte Carlo Normal Mode Following (MC-NMF) technique, one applicable even without a target structure. The results demonstrate that the lowest-frequency normal mode (NM) at ∼6.5 cm−1 is the crucial mode that initiates dissociation. Perturbing the gA dimer in either direction along this NM leads to opposed, nearly rigid-body rotations of the gA monomers around the central pore axis. Tracking this NM by using the eigenvector-following technique reveals the channel's gating mechanism: dissociation via relative opposed monomer rotation and simultaneous lateral displacement. System evolution along the lowest-frequency eigenvector shows that the large-amplitude motions required for gating (dissociation) are not simple relative rigid-body motions of the monomers. Gating involves coupling intermonomer hydrogen bond breaking, backbone realignment, and relative monomer tilt with complex side chain reorganization at the intermonomer junction.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: - Volume 14, Issue 8, August 2006, Pages 1241–1249
نویسندگان
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