Green/red cyanobacteriochromes regulate complementary chromatic acclimation via a protochromic photocycle.

ABSTRACT: Cyanobacteriochromes (CBCRs) are cyanobacterial members of the phytochrome superfamily of photosensors. Like phytochromes, CBCRs convert between two photostates by photoisomerization of a covalently bound linear tetrapyrrole (bilin) chromophore. Although phytochromes are red/far-red sensors, CBCRs exhibit diverse photocycles spanning the visible spectrum and the near-UV (330-680 nm). Two CBCR subfamilies detect near-UV to blue light (330-450 nm) via a "two-Cys photocycle" that couples bilin 15Z/15E photoisomerization with formation or elimination of a second bilin-cysteine adduct. On the other hand, mechanisms for tuning the absorption between the green and red regions of the spectrum have not been elucidated as of yet. CcaS and RcaE are members of a CBCR subfamily that regulates complemen

SUBMITTER: Hirose Y 

PROVIDER: S-EPMC3612671 | biostudies-literature | 2013 Mar

REPOSITORIES: biostudies-literature