A look within LHCII: Differential analysis of the Lhcb1-3 complexes building the major trimeric antenna complex of higher-plant photosynthesis

Stefano Caffarri, Roberta Croce, Luigi Cattivelli, Roberto Bassi*

*Corresponding author for this work

Research output: Contribution to JournalArticleAcademicpeer-review

Abstract

The major antenna complex of higher-plant photosynthesis, LHCII, is composed by the products of three genes, namely, Lhcb1-2-3. In this paper, the biochemical and spectroscopic properties of each of the three gene products were investigated. The three complexes were obtained by overexpression of the apoproteins in bacteria and refolding in vitro with purified pigments, thus allowing detection of differences in the structure/function of the pigment-binding gene products. The analyses showed that Lhcb1 and Lhcb2 complexes have similar pigment binding properties, although not identical, while Lhcb3 is clearly different with respect to both pigment binding and spectral properties and cannot produce homotrimers in vitro. Heterotrimers containing Lhcb3 together with Lhcb1 and/or -2 proteins were obtained upon assembly with Lhcb proteins purified from thylakoids. The major functional characteristics of Lhcb3 with respect to Lhcb1 and -2 consisted in (i) a red-shift of one specific chlorophyll a chromophore, strongly affecting the red-most region of the absorption spectrum and (ii) a different specificity for xanthophylls binding to sites L2 and N1. These properties make Lhcb3 a relative sink for excitation energy in isolated heterotrimers with Lhcb1 + Lhcb2, and potentially, a preferential site of regulation of the antenna function in excess light conditions.

Original languageEnglish
Pages (from-to)9467-9476
Number of pages10
JournalBiochemistry
Volume43
Issue number29
DOIs
Publication statusPublished - 27 Jul 2004

Fingerprint

Dive into the research topics of 'A look within LHCII: Differential analysis of the Lhcb1-3 complexes building the major trimeric antenna complex of higher-plant photosynthesis'. Together they form a unique fingerprint.

Cite this