This Article Full Text Full Text (PDF) Supplement A correction has been published All Versions of this Article: biophysj.106.088609v1 91/10/3630    most recent Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Freddolino, P. L. Articles by Schulten, K. Search for Related Content PubMed PubMed Citation Articles by Freddolino, P. L. Articles by Schulten, K.

Dynamic Switching Mechanisms in LOV1 and LOV2 Domains of Plant Phototropins

Peter L. Freddolino ^* , Markus Dittrich   and Klaus Schulten ^*  

^* Center for Biophysics and Computational Biology, Beckman Institute, and Department of Physics, University of Illinois at Urbana-Champaign, Urbana, Illinois

Correspondence: Address reprint requests to K. Schulten, E-mail: kschulte{at}ks.uiuc.edu.

LOV domains are the light-sensitive portion of plant phototropins. They absorb light through a flavin cofactor, photochemically form a covalent bond between the chromophore and a cysteine residue in the protein, and proceed to mediate activation of an attached kinase domain. Although the photoreaction itself is now well-characterized experimentally and computationally, it is still unclear how the formation of the adduct leads to kinase activation. We have performed molecular dynamics simulations on the LOV1 domain of Chlamydomonas reinhardtii and the LOV2 domain of Avena sativa, both before and after the photoreaction, to answer this question. The extensive simulations, over 240 ns in duration, reveal significant differences in how the LOV1 and LOV2 domains respond to photoactivation. The simulations indicate that LOV1 activation is likely caused by a change in hydrogen bonding between protein and ligand that destabilizes a highly conserved salt bridge, whereas LOV2 activation seems to result from a change in the flexibility of a set of protein loops. Results of electrostatics calculations, principal component analysis, sequence alignments, and root mean-square deviation analysis corroborate the above findings.

This article has been cited by other articles:

				Z. Cao, V. Buttani, A. Losi, and W. Gartner A Blue Light Inducible Two-Component Signal Transduction System in the Plant Pathogen Pseudomonas syringae pv. tomato Biophys. J., February 1, 2008; 94(3): 897 - 905. [Abstract] [Full Text] [PDF]