2bhw | pdb_00002bhw

File:2bhw.gif

spinqualitylabelsall models Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D load='2bhw' size='350' frame='false' scene=
2bhw, resolution 2.5Å
Sites:	AC1
Ligands:	LUX, NEX, XAT, CLA, CHL, LHG and DGD
Coordinates:	save as pdb, mmCIF, xml

PEA LIGHT-HARVESTING COMPLEX II AT 2.5 ANGSTROM RESOLUTION

Overview

The plant light-harvesting complex of photosystem II (LHC-II) collects and transmits solar energy for photosynthesis in chloroplast membranes and has essential roles in regulation of photosynthesis and in photoprotection. The 2.5 A structure of pea LHC-II determined by X-ray crystallography of stacked two-dimensional crystals shows how membranes interact to form chloroplast grana, and reveals the mutual arrangement of 42 chlorophylls a and b, 12 carotenoids and six lipids in the LHC-II trimer. Spectral assignment of individual chlorophylls indicates the flow of energy in the complex and the mechanism of photoprotection in two close chlorophyll a-lutein pairs. We propose a simple mechanism for the xanthophyll-related, slow component of nonphotochemical quenching in LHC-II, by which excess energy is transferred to a zeaxanthin replacing violaxanthin in its binding site, and dissipated as heat. Our structure shows the complex in a quenched state, which may be relevant for the rapid, pH-induced component of nonphotochemical quenching.

About this Structure

2BHW is a Single protein structure of sequence from Pisum sativum. Full crystallographic information is available from OCA.

Reference

Mechanisms of photoprotection and nonphotochemical quenching in pea light-harvesting complex at 2.5 A resolution., Standfuss J, Terwisscha van Scheltinga AC, Lamborghini M, Kuhlbrandt W, EMBO J. 2005 Mar 9;24(5):919-28. Epub 2005 Feb 17. PMID:15719016

Page seeded by OCA on Sun Mar 23 14:45:06 2008

Proteopedia Page Contributors and Editors (what is this?)

OCA