The light-harvesting antenna of the diatom Phaeodactylum tricornutum. Evidence for a diadinoxanthin-binding subcomplex.

FEBS J

Organismes Photosynthétiques et Environnement, CNRS, Département de Biologie, Ecole Normale Supérieure, Paris, France.

Published: September 2005

Diatoms differ from higher plants by their antenna system, in terms of both polypeptide and pigment contents. A rapid isolation procedure was designed for the membrane-intrinsic light harvesting complexes (LHC) of the diatom Phaeodactylum tricornutum to establish whether different LHC subcomplexes exist, as well to determine an uneven distribution between them of pigments and polypeptides. Two distinct fractions were separated that contain functional oligomeric complexes. The major and more stable complex ( approximately 75% of total polypeptides) carries most of the chlorophyll a, and almost only one type of carotenoid, fucoxanthin. The minor complex, carrying approximately 10-15% of the total antenna chlorophyll and only a little chlorophyll c, is highly enriched in diadinoxanthin, the main xanthophyll cycle carotenoid. The two complexes also differ in their polypeptide composition, suggesting specialized functions within the antenna. The diadinoxanthin-enriched complex could be where the de-epoxidation of diadinoxanthin into diatoxanthin mostly occurs.

Download full-text PDF

Source
http://dx.doi.org/10.1111/j.1742-4658.2005.04846.xDOI Listing

Publication Analysis

Top Keywords

diatom phaeodactylum
8
phaeodactylum tricornutum
8
light-harvesting antenna
4
antenna diatom
4
tricornutum evidence
4
evidence diadinoxanthin-binding
4
diadinoxanthin-binding subcomplex
4
subcomplex diatoms
4
diatoms differ
4
differ higher
4

Similar Publications

Many important processes in cells depend on the transfer of protons through water wires embedded in transmembrane proteins. Herein, we have performed more than 55 μs all-atom simulations of the light-harvesting complex of a diatom, i.e.

View Article and Find Full Text PDF

Background: Phaeodactylum tricornutum is a versatile marine microalga renowned for its high-value metabolite production, including omega-3 fatty acids and fucoxanthin, with emerging potential for integrated biorefinery approaches that encompass biofuel and bioproduct generation. Therefore, in this study we aimed to optimize the cultivation conditions for boosting biomass, lipid, and fucoxanthin production in P. tricornutum, focusing on the impacts of different nutrient ratios (nitrogen, phosphorus, silicate), glycerol supplementation, and light regimes.

View Article and Find Full Text PDF

Diatoms dominate phytoplankton communities in turbulent waters, where light fluctuations can be frequent and intense. Due to this complex environment, these heterokont microalgae display remarkable photoprotection strategies, including a fast Non-Photochemical Quenching (NPQ). However, in nature, several abiotic parameters (such as temperature) can influence the response of photosynthetic organisms to light stress in a synergistic or antagonistic manner.

View Article and Find Full Text PDF

A major obstacle to exploiting industrial flue gas for microalgae cultivation is the unfavorable acidic environment. We previously identified three upregulated genes in the low-pH-adapted model diatom : ferredoxin (PtFDX), cation/proton antiporter (PtCPA), and HCO transporter (PtSCL4-2). Here, we individually overexpressed these genes in to investigate their respective roles in resisting acidic stress (pH 5.

View Article and Find Full Text PDF

This study presents characterisation of diatom's PtLPCAT1 (acyl-CoA: lysophosphatidylcholine acyltransferase) activity in phospholipid remodelling. In this research microsomal fractions of yeast Δale1 mutant overexpressing PtLPCAT1 were used as a source of the tested enzyme. In the assays evaluating remodelling of different phospholipids by PtLPCAT1 not modified microsomal fractions of the tested yeast were used.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!