This Article Full Text Full Text (PDF) 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 Ataka, K. Articles by Heberle, J. Search for Related Content PubMed PubMed Citation Articles by Ataka, K. Articles by Heberle, J.

Vibrational Spectroscopy of an Algal Phot-LOV1 Domain Probes the Molecular Changes Associated with Blue-Light Reception

K. Ataka^*, P. Hegemann and J. Heberle^*

^* Forschungszentrum Jülich, IBI-2: Structural Biology, 52425 Jülich, Germany, and Institut für Biochemie I, Universität Regensburg, Universitätsstrasse 31, D-93053 Regensburg, Germany

Correspondence: Address reprint requests to J. Heberle, Tel.: +49-2461-61-2024; Fax: +49-2461-61-2020; E-mail: j.heberle{at}fz-juelich.de.

The LOV1 domain of the blue light Phot1-receptor (phototropin homolog) from Chlamydomonas reinhardtii has been studied by vibrational spectroscopy. The FMN modes of the dark state of LOV1 were identified by preresonance Raman spectroscopy and assigned to molecular vibrations. By comparing the blue-light-induced FTIR difference spectrum with the preresonance Raman spectrum, most of the differences are due to FMN modes. Thus, we exclude large backbone changes of the protein that might occur during the phototransformation of the dark state LOV1-447 into the putative signaling state LOV1-390. Still, the presence of smaller amide difference bands cannot be excluded but may be masked by overlapping FMN modes. The band at 2567 cm^-1 is assigned to the S-H stretching vibration of C57, the residue that forms the transient thio-adduct with the chromophore FMN. The occurrence of this band is evidence that C57 is protonated in the dark state of LOV1. This result challenges conclusions from the homologous LOV2 domain from oat that the thiolate of the corresponding cysteine is the reactive species.

This article has been cited by other articles:

				C. Bonetti, T. Mathes, I. H. M. van Stokkum, K. M. Mullen, M.-L. Groot, R. van Grondelle, P. Hegemann, and J. T. M. Kennis Hydrogen Bond Switching among Flavin and Amino Acid Side Chains in the BLUF Photoreceptor Observed by Ultrafast Infrared Spectroscopy Biophys. J., November 15, 2008; 95(10): 4790 - 4802. [Abstract] [Full Text] [PDF]

				H. Guo, T. Kottke, P. Hegemann, and B. Dick The Phot LOV2 Domain and Its Interaction with LOV1 Biophys. J., July 1, 2005; 89(1): 402 - 412. [Abstract] [Full Text] [PDF]

				K. Hasegawa, S. Masuda, and T.-a. Ono Spectroscopic Analysis of the Dark Relaxation Process of a Photocycle in a Sensor of Blue Light using FAD (BLUF) Protein Slr1694 of the Cyanobacterium Synechocystis sp. PCC6803 Plant Cell Physiol., January 15, 2005; 46(1): 136 - 146. [Abstract] [Full Text] [PDF]

				A. Losi, T. Kottke, and P. Hegemann Recording of Blue Light-Induced Energy and Volume Changes within the Wild-Type and Mutated Phot-LOV1 Domain from Chlamydomonas reinhardtii Biophys. J., February 1, 2004; 86(2): 1051 - 1060. [Abstract] [Full Text] [PDF]

				T. Kottke, J. Heberle, D. Hehn, B. Dick, and P. Hegemann Phot-LOV1: Photocycle of a Blue-Light Receptor Domain from the Green Alga Chlamydomonas reinhardtii Biophys. J., February 1, 2003; 84(2): 1192 - 1201. [Abstract] [Full Text] [PDF]