TCB Publications - Abstract

Peter L. Freddolino, Kevin H. Gardner, and Klaus Schulten. Signaling mechanisms of LOV domains: new insights from molecular dynamics studies. Photochemical & Photobiological Sciences, 12:1158-1170, 2013. (PMC: 3679247)

FRED2013 Phototropins are one of several classes of photoreceptors used by plants and algae to respond to light. These proteins contain flavin-binding LOV (Light-Oxygen-Voltage) domains that form covalent cysteineflavin adducts upon exposure to blue light, leading to the enhancement of phototropin kinase activity. Several lines of evidence suggest that adduct formation in the phototropin LOV2 domains leads to the dissociation of an alpha helix (J$\alpha$) from these domains as part of the light-induced activation process. However, crystal structures of LOV domains both in the presence and absence of the J$\alpha$ helix show very few differences between dark and illuminated states, and thus the precise mechanism through which adduct formation triggers helical dissociation remains poorly understood. Using Avena sativa phototropin 1 LOV2 as a model system, we have studied the interactions of the LOV domain core with the J$\alpha$ helix through a series of equilibrium molecular dynamics simulations. Here we show that conformational transitions of a conserved glutamine residue in the flavin binding pocket are coupled to altered dynamics of the J$\alpha$ helix both through a shift in dynamics of the main $\beta$-sheet of the LOV domain core and through a secondary pathway involving the N-terminal A$\alpha$ helix.



Download Full Text

The manuscripts available on our site are provided for your personal use only and may not be retransmitted or redistributed without written permissions from the paper's publisher and author. You may not upload any of this site's material to any public server, on-line service, network, or bulletin board without prior written permission from the publisher and author. You may not make copies for any commercial purpose. Reproduction or storage of materials retrieved from this web site is subject to the U.S. Copyright Act of 1976, Title 17 U.S.C.

Download full text: Supplemental Material ( 1.4MB) - Supplementary PDF, Supplemental Material (32.3MB) - Supplementary movie S1, Supplemental Material (30.0MB) - Supplementary movie S2, Supplemental Material ( 9.8KB) - Supplementary force field files, Journal, Request a Copy, Additional Information