The University of Southampton
University of Southampton Institutional Repository

Structure of a photosystem II supercomplex isolated from Prochloron didemni retaining its chlorophyll a/b light-harvesting system

Bibby, Thomas S., Nield, Jon, Chen, Min, Larkum, Anthony W.D. and Barber, James (2003) Structure of a photosystem II supercomplex isolated from Prochloron didemni retaining its chlorophyll a/b light-harvesting system Proceedings of the National Academy of Sciences, 100, (15), pp. 9050-9054. (doi:10.1073/pnas.1532271100).

Record type: Article


Prochlorophytes are a class of cyanobacteria that do not use phycobiliproteins as light-harvesting systems, but contain chlorophyll (Chl) a/b-binding Pcb proteins. Recently it was shown that Pcb proteins form an 18-subunit light-harvesting antenna ring around the photosystem I (PSI) trimeric reaction center complex of the prochlorophyte Prochlorococcus marinus SS120. Here we have investigated whether the symbiotic prochlorophyte Prochloron didemni also contains the same supermolecular complex. Using cells isolated directly from its ascidian host, we found no evidence for the presence of the Pcb-PSI supercomplex. Instead we have identified and characterized a supercomplex composed of photosystem II (PSII) and Pcb proteins. We show that 10-Pcb subunits associate with the PSII dimeric reaction center core to form a giant complex having an estimated Mr of 1,500 kDa with dimensions of 210 x 290 A. Five-Pcb subunits flank each long side of the dimer and assuming each binds 13 Chl molecules, increase the antenna size of PSII by approximately 200%. Fluorescence emission studies indicate that energy transfer occurs efficiently from the Pcb antenna. Modeling using the x-ray structure of cyanobacterial PSII suggests that energy transfer to the PSII reaction center is via the Chls bound to the CP47 and CP43 proteins.

Full text not available from this repository.

More information

Published date: 22 July 2003
Organisations: Ocean and Earth Science


Local EPrints ID: 37560
ISSN: 0027-8424
PURE UUID: 0bd7459c-32f1-49be-b705-58c4fd2442bd

Catalogue record

Date deposited: 23 May 2006
Last modified: 17 Jul 2017 15:42

Export record



Author: Thomas S. Bibby
Author: Jon Nield
Author: Min Chen
Author: Anthony W.D. Larkum
Author: James Barber

University divisions

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton:

ePrints Soton supports OAI 2.0 with a base URL of

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.