Publication

Article Metrics

Citations


Online attention

The negatively charged amino acids in the lumenal loop influence the pigment binding and conformation of the major light-harvesting chlorophyll a/b complex of photosystem II

DOI: 10.1016/j.bbabio.2008.08.009 DOI Help

Authors: C. H. Yang (Chinese Academy of Sciences; Institut f. Allgemeine Botanik, Johannes-Gutenberg-Universit├Ąt Mainz) , P. Lambrev (Institute of Plant Biology, Hungarian Academy of Sciences) , Z. Chen (Chinese Academy of Sciences) , A. Z. Kiss (Institute of Plant Biology, Hungarian Academy of Sciences) , H. Paulsen (Institut f. Allgemeine Botanik, Johannes-Gutenberg-Universit├Ąt Mainz) , G. Garab (Institute of Plant Biology, Hungarian Academy of Sciences) , T. Javorfi (Institute of Plant Biology, Hungarian Academy of Sciences)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Biochimica Et Biophysica Acta (bba) - Bioenergetics , VOL 1777 (11) , PAGES 1463-14

State: Published (Approved)
Published: September 2008

Abstract: The major chlorophyll (Chl) a/b complexes of photosystem II (LHCIIb), in addition to their primary light-harvesting function, play key roles in the organization of the granal ultrastructure of the thylakoid membranes and in various regulatory processes. These functions depend on the structural stability and flexibility of the complexes. The lumenal side of LHCIIb is exposed to broadly variable pH environments, due to the build-up and decay of the pH gradient during photosynthesis. Therefore, the negatively charged amino acids in the lumenal loop might be of paramount importance for adjusting the structure and functions of LHCIIb. In order to clarify the structural roles of these residues, we investigated the pigment stoichiometries, absorption, linear and circular dichroism spectra of the reconstituted LHCIIb complexes, in which the negatively charged amino acids in the lumenal loop were exchanged to neutral ones (E94G, E107V and D111V). The mutations influenced the pigment binding and the molecular architecture of the complexes. Exchanging E94 to G destabilized the 310 helix in the lumenal loop structure and led to an acquired pH sensitivity of the LHCIIb structure. We conclude that these amino acids are important not only for pigment binding in the complexes, but also in stabilizing the conformation of LHCIIb at different pHs.

Journal Keywords: Major Light-Harvesting A/B Complex Of Photosystem Ii; Spectroscopy; Mutagenesis; Low Ph

Subject Areas: Biology and Bio-materials, Chemistry


Instruments: NONE-No attached Diamond beamline

Discipline Tags:



Technical Tags: