Photosystem II macro-organization

Photosystem II (PSII) is a multisubunit complex, which uses light energy to split water into oxygen, protons, and electrons. The light-harvesting complex of PSII (LHCII) functions in the capture of light energy and its transmission to chlorophyll molecules of PSII. The LHCII proteins Lhcb1-3 form a heterotrimer, whilst the three remaining subunits, Lhcb4 (CP29), Lhcb5 (CP26) and Lhcb6 (CP24) are monomeric. In the February 6 Nature, Alexander Ruban and colleagues at the University of Sheffield, UK, show that the macro-organization of PSII is retained in the absence of the main light harvesting complex (Nature, 421:648-652, February 6, 2003).

Ruban et al. constructed an Lhcb2 antisense Abrabidopsis thaliana mutant. They observed that whilst there were phenotypic differences between the antisense and wild type plants, there was no difference in PSII activity. In mutant plants Lhcb2 levels were about 5% of wild type and Lhcb1 was completely absent, but the levels of ...