title: Energy Transfer in Cyanobacteria and Red Algae: Confirmation of Spillover in Intact Megacomplexes of Phycobilisome and Both Photosystems.
abstract: Cyanobacteria and red algae control the energy distributions of two photosystems (PSI and PSII) by changing the energy transfer among phycobilisome (PBS), PSI, and PSII. However, whether PSII → PSI energy transfer (spillover) occurs in the intact megacomplexes composed of PBS, PSI, and PSII (PBS-PSII-PSI megacomplexes) in vivo remains controversial. In this study, we measured the delayed fluorescence spectra of PBS-selective excitation in cyanobacterial and red algal cells. In the absence of spillover, 7% of the PBS (at most) would combine with PSII, inconsistent with the PBSs' function as the antenna pigment-protein complexes of PSII. Therefore, we conclude that spillover occurs in vivo in PBS-PSII-PSI megacomplexes of both cyanobacteria and red algae.
authors: Graduate School of Science, ‡Graduate School of Engineering, and §Molecular Photoscience Research Center, Kobe University , Kobe 657-8501, Japan.
authors: Yoshifumi
authors: Y
authors: Ueno
authors: Graduate School of Science, ‡Graduate School of Engineering, and §Molecular Photoscience Research Center, Kobe University , Kobe 657-8501, Japan.
authors: Shimpei
authors: S
authors: Aikawa
authors: Graduate School of Science, ‡Graduate School of Engineering, and §Molecular Photoscience Research Center, Kobe University , Kobe 657-8501, Japan.
authors: Akihiko
authors: A
authors: Kondo
authors: Graduate School of Science, ‡Graduate School of Engineering, and §Molecular Photoscience Research Center, Kobe University , Kobe 657-8501, Japan.
authors: Seiji
authors: S
authors: Akimoto
mesh_terms: D000458:Cyanobacteria / Q000737:chemistry*; D045331:Photosystem I Protein Complex / Q000737:chemistry*; D045524:Phycobilisomes / Q000737:chemistry*; D000461:Rhodophyta / Q000737:chemistry*
chemical_list: D045331:Photosystem I Protein Complex; D045524:Phycobilisomes