6BHO

Green Light-Absorbing State of NpR6012g4, a Red/Green Cyanobacteriochrome

6BHO の概要

• エントリーDOI: 10.2210/pdb6bho/pdb
• 関連するPDBエントリー: 6BHN
• NMR情報: BMRB: 26577
• 分子名称: Methyl-accepting chemotaxis sensory transducer with phytochrome sensor, PHYCOCYANOBILIN (2 entities in total)
• 機能のキーワード: cbcr, phytochrome, bilin, cyanobacteria, signaling protein
• 由来する生物種: Nostoc punctiforme PCC 73102
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 20990.50

構造登録者

Lim, S.,Yu, Q.,Rockwell, N.C.,Martin, S.S.,Lagarias, J.C.,Ames, J.B. (登録日: 2017-10-31, 公開日: 2018-04-18, 最終更新日: 2024-10-23)

主引用文献

Lim, S.,Yu, Q.,Gottlieb, S.M.,Chang, C.W.,Rockwell, N.C.,Martin, S.S.,Madsen, D.,Lagarias, J.C.,Larsen, D.S.,Ames, J.B.
Correlating structural and photochemical heterogeneity in cyanobacteriochrome NpR6012g4.
Proc. Natl. Acad. Sci. U.S.A., 115:4387-4392, 2018

PubMed Abstract: Phytochrome photoreceptors control plant growth, development, and the shade avoidance response that limits crop yield in high-density agricultural plantings. Cyanobacteriochromes (CBCRs) are distantly related photosensory proteins that control cyanobacterial metabolism and behavior in response to light. Photoreceptors in both families reversibly photoconvert between two photostates via photoisomerization of linear tetrapyrrole (bilin) chromophores. Spectroscopic and biochemical studies have demonstrated heterogeneity in both photostates, but the structural basis for such heterogeneity remains unclear. We report solution NMR structures for both photostates of the red/green CBCR NpR6012g4 from In addition to identifying structural changes accompanying photoconversion, these structures reveal structural heterogeneity for residues Trp655 and Asp657 in the red-absorbing NpR6012g4 dark state, yielding two distinct environments for the phycocyanobilin chromophore. We use site-directed mutagenesis and fluorescence and absorbance spectroscopy to assign an orange-absorbing population in the NpR6012g4 dark state to the minority configuration for Asp657. This population does not undergo full, productive photoconversion, as shown by time-resolved spectroscopy and absorption spectroscopy at cryogenic temperature. Our studies thus elucidate the spectral and photochemical consequences of structural heterogeneity in a member of the phytochrome superfamily, insights that should inform efforts to improve photochemical or fluorescence quantum yields in the phytochrome superfamily.

PubMed: 29632180
DOI: 10.1073/pnas.1720682115

実験手法

SOLUTION NMR