skip to main content

DOE PAGESDOE PAGES

Title: Structural insights into the light-driven auto-assembly process of the water-oxidizing Mn 4CaO 5-cluster in photosystem II

In plants, algae and cyanobacteria, Photosystem II (PSII) catalyzes the light-driven splitting of water at a protein-bound Mn 4CaO 5-cluster, the water-oxidizing complex (WOC). In the photosynthetic organisms, the light-driven formation of the WOC from dissolved metal ions is a key process because it is essential in both initial activation and continuous repair of PSII. Structural information is required for understanding of this chaperone-free metal-cluster assembly. For the first time, we obtained a structure of PSII from Thermosynechococcus elongatus without the Mn 4CaO 5-cluster. Surprisingly, cluster-removal leaves the positions of all coordinating amino acid residues and most nearby water molecules largely unaffected, resulting in a pre-organized ligand shell for kinetically competent and error-free photo-assembly of the Mn 4CaO 5-cluster. First experiments initiating (i) partial disassembly and (ii) partial re-assembly after complete depletion of the Mn4CaO5-cluster agree with a specific bi-manganese cluster, likely a di-µ-oxo bridged pair of Mn(III) ions, as an assembly intermediate.
Authors:
ORCiD logo [1] ;  [1] ;  [2] ;  [1] ;  [2] ;  [3] ;  [2] ; ORCiD logo [1] ; ORCiD logo [1]
  1. Humboldt Univ. of Berlin (Germany). Inst. of Biology
  2. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
  3. Freie Univ., Berlin (Germany)
Publication Date:
Grant/Contract Number:
AC02-05CH11231
Type:
Accepted Manuscript
Journal Name:
eLife
Additional Journal Information:
Journal Volume: 6; Journal ID: ISSN 2050-084X
Publisher:
eLife Sciences Publications, Ltd.
Research Org:
Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
Country of Publication:
United States
Language:
English
Subject:
60 APPLIED LIFE SCIENCES; 59 BASIC BIOLOGICAL SCIENCES
OSTI Identifier:
1408448