Hydrophobic Residues near the Bilin Chromophore-Binding Pocket Modulate Spectral Tuning of Insert-Cys Subfamily Cyanobacteriochromes

Cited 5 time in webofscience Cited 0 time in scopus
  • Hit : 366
  • Download : 162
Cyanobacteriochromes (CBCRs) are a subfamily of phytochrome photoreceptors found exclusively in photosynthetic cyanobacteria. Four CBCRs containing a second Cys in the insert region (insert-Cys) have been identified from the nonheterocystous cyanobacterium Microcoleus B353 (Mbr3854g4 and Mbl3738g2) and the nitrogen fixing, heterocystous cyanobacterium Nostoc punctiforme (NpF2164g3 and NpR1597g2). These insert-Cys CBCRs can sense light in the near-UV to orange range, but key residues responsible for tuning their colour sensitivity have not been reported. In the present study, near-UV/Green (UG) photosensors Mbr3854g4 (UG1) and Mbl3738g2 (UG2) were chosen for further spectroscopic analysis of their spectral sensitivity and tuning. Consistent with most dual-Cys CBCRs, both UGs formed a second thioether linkage to the phycocyanobilin (PCB) chromophore via the insert-Cys. This bond is subject to breakage and relinkage during forward and reverse photoconversions. Variations in residues equivalent to Phe that are in close contact with the PCB chromophore D-ring in canonical red/green CBCRs are responsible for tuning the light absorption peaks of both dark and photoproducts. This is the first time these key residues that govern light absorption in insert-Cys family CBCRs have been identified and characterised.
Publisher
NATURE PUBLISHING GROUP
Issue Date
2017-01
Language
English
Article Type
Article
Keywords

SP PCC 6803; GAF DOMAIN; THERMOSYNECHOCOCCUS-ELONGATUS; REVERSIBLE PHOTOCONVERSION; DXCF-CYANOBACTERIOCHROMES; NEGATIVE PHOTOTAXIS; NOSTOC-PUNCTIFORME; CELL-AGGREGATION; LIGHT; PHYTOCHROME

Citation

SCIENTIFIC REPORTS, v.7

ISSN
2045-2322
DOI
10.1038/srep40576
URI
http://hdl.handle.net/10203/220725
Appears in Collection
BS-Journal Papers(저널논문)
Files in This Item
000391939400001.pdf(2.45 MB)Download
This item is cited by other documents in WoS
⊙ Detail Information in WoSⓡ Click to see webofscience_button
⊙ Cited 5 items in WoS Click to see citing articles in records_button

qr_code

  • mendeley

    citeulike


rss_1.0 rss_2.0 atom_1.0