Visual Pigments as Photoreceptors

Kumauchi, Masato; Ebrey, Thomas G.

doi:10.1002/352760510x.ch3

Cited by 8 publications

(6 citation statements)

References 119 publications

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“…This shows that PYP has a highly conserved chromophore binding pocket, similar to that described for rhodopsin (see e.g. Kumauchi and Ebrey [73]). The nine residues forming this conserved p CA binding pocket are Ile31, Tyr42, Glu46, Phe62, Val66, Ala67, Pro68, Cys69 and Phe96.…”

Section: Resultssupporting

confidence: 73%

Identification of Six New Photoactive Yellow Proteins—Diversity and Structure–Function Relationships in a Bacterial Blue Light Photoreceptor^†

Kumauchi

Hara

Stalcup

et al. 2008

Photochem & Photobiology

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102

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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 pK(a) 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.

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Section: Resultssupporting

confidence: 73%

Identification of Six New Photoactive Yellow Proteins—Diversity and Structure–Function Relationships in a Bacterial Blue Light Photoreceptor^†

Kumauchi

Hara

Stalcup

et al. 2008

Photochem & Photobiology

Self Cite

102

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“… Schematic representation of bovine rhodopsin inserted in the disc membrane. On the basis of crystallographic data . H1–H7, transmembrane α ‐helices; H8, short cytoplasmic α ‐helix.…”

Section: Photosensory Proteinsmentioning

confidence: 99%

The evolution of vision

Gehring¹

2012

WIREs Developmental Biology

122

105

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In this review, the evolution of vision is retraced from its putative origins in cyanobacteria to humans. Circadian oscillatory clocks, phototropism, and phototaxis require the capability to detect light. Photosensory proteins allow us to reconstruct molecular phylogenetic trees. The evolution of animal eyes leading from an ancestral prototype to highly complex image forming eyes can be deciphered on the basis of evolutionary developmental genetic experiments and comparative genomics. As all bilaterian animals share the same master control gene, Pax6, and the same retinal and pigment cell determination genes, we conclude that the different eye-types originated monophyletically and subsequently diversified by divergent, parallel, or convergent evolution.

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“…Rhodopsins are light-sensing photoreceptor proteins widely distributed in Eukaryota, Bacteria, and Archaea, − capable of absorbing a wide range of wavelengths. Most animal and microbial rhodopsins bind a retinal chromophore with a protonated Schiff base, which enables tuning their absorbance maxima throughout the visible part of the electromagnetic spectrum, from the blue to the red. , Rhodopsins rely on light-driven isomerization of the retinal chromophore for their photoactivated functions.…”

Section: Introductionmentioning

confidence: 99%

Dual Photoisomerization on Distinct Potential Energy Surfaces in a UV-Absorbing Rhodopsin

et al. 2020

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UV-absorbing rhodopsins are essential for UV vision and sensing in all kingdoms of life. Unlike the well-known visible-absorbing rhodopsins, which bind a protonated retinal Schiff base for light absorption, UV-absorbing rhodopsins bind an unprotonated retinal Schiff base. Thus far, the photoreaction dynamics and mechanisms of UV-absorbing rhodopsins have remained essentially unknown. Here, we report the complete excited- and ground-state dynamics of the UV form of histidine kinase rhodopsin 1 (HKR1) from eukaryotic algae, using femtosecond stimulated Raman spectroscopy (FSRS) and transient absorption spectroscopy, covering time scales from femtoseconds to milliseconds. We found that energy-level ordering is inverted with respect to visible-absorbing rhodopsins, with an optically forbidden low-lying S1 excited state that has Ag– symmetry and a higher-lying UV-absorbing S2 state of Bu+ symmetry. UV-photoexcitation to the S2 state elicits a unique dual-isomerization reaction: first, C13C14 cis–trans isomerization occurs during S2–S1 evolution in <100 fs. This very fast reaction features the remarkable property that the newly formed isomer appears in the excited state rather than in the ground state. Second, C15N16 anti–syn isomerization occurs on the S1–S0 evolution to the ground state in 4.8 ps. We detected two ground-state unprotonated retinal photoproducts, 13-trans/15-anti (all-trans) and 13-cis/15-syn, after relaxation to the ground state. These isomers become protonated in 58 μs and 3.2 ms, respectively, resulting in formation of the blue-absorbing form of HKR1. Our results constitute a benchmark of UV-induced photochemistry of animal and microbial rhodopsins.

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Visual Pigments as Photoreceptors

Cited by 8 publications

References 119 publications

Identification of Six New Photoactive Yellow Proteins—Diversity and Structure–Function Relationships in a Bacterial Blue Light Photoreceptor^†

Identification of Six New Photoactive Yellow Proteins—Diversity and Structure–Function Relationships in a Bacterial Blue Light Photoreceptor^†

The evolution of vision

Dual Photoisomerization on Distinct Potential Energy Surfaces in a UV-Absorbing Rhodopsin

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Visual Pigments as Photoreceptors

Cited by 8 publications

References 119 publications

Identification of Six New Photoactive Yellow Proteins—Diversity and Structure–Function Relationships in a Bacterial Blue Light Photoreceptor†

Identification of Six New Photoactive Yellow Proteins—Diversity and Structure–Function Relationships in a Bacterial Blue Light Photoreceptor†

The evolution of vision

Dual Photoisomerization on Distinct Potential Energy Surfaces in a UV-Absorbing Rhodopsin

Contact Info

Product

Resources

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Identification of Six New Photoactive Yellow Proteins—Diversity and Structure–Function Relationships in a Bacterial Blue Light Photoreceptor^†

Identification of Six New Photoactive Yellow Proteins—Diversity and Structure–Function Relationships in a Bacterial Blue Light Photoreceptor^†