These authors have contributed equally to this work.
Identification of Six New Photoactive Yellow Proteins—Diversity and Structure–Function Relationships in a Bacterial Blue Light Photoreceptor†
Article first published online: 9 APR 2008
© 2008 The Authors. Journal Compilation. The American Society of Photobiology
Photochemistry and Photobiology
Volume 84, Issue 4, pages 956–969, July/August 2008
How to Cite
Kumauchi, M., Hara, M. T., Stalcup, P., Xie, A. and Hoff, W. D. (2008), Identification of Six New Photoactive Yellow Proteins—Diversity and Structure–Function Relationships in a Bacterial Blue Light Photoreceptor. Photochemistry and Photobiology, 84: 956–969. doi: 10.1111/j.1751-1097.2008.00335.x
This invited paper is part of the Symposium-in-Print: Photoreceptors and Signal Transduction.
- Issue published online: 9 JUL 2008
- Article first published online: 9 APR 2008
- Received 19 December 2007, accepted 9 February 2008
Photoactive yellow proteins (PYP) are bacterial photoreceptors with a Per-Arnt-Sim (PAS) domain fold. We report the identification of six new PYPs, thus nearly doubling the size of this protein family. This extends the taxonomic diversity of PYP-containing bacteria from photosynthetic to nonphotosynthetic bacteria, from aquatic to soil-dwelling organisms, and from Proteobacteria to Salinibacter ruber from the phylum Bacteriodetes. The new PYPs greatly increase the sequence diversity of the PYP family, reducing the most prevalent pair-wise identity from 45% to 25%. Sequence alignments and analysis indicate that all 14 PYPs share a common structure with 13 highly conserved residues that form the chromophore binding pocket. Nevertheless, the functional properties of the PYPs vary greatly—the absorbance maximum extends from 432 to 465 nm, the pKa of the chromophore varies from pH 2.8 to 10.2, and the lifetime of the presumed PYP signaling state ranges from 1 ms to 1 h. Thus, the PYP family offers an excellent opportunity to investigate how functional properties are tuned over a wide range, while maintaining the same overall protein structural fold. We discuss the implications of these results for structure–function relationships in the PYP family.