Obscurity of chlorophyll tails - Is chlorophyll with farnesyl tail incorporated into PSII complexes?

Graça AT, Lihavainen J, Hussein R, Schröder WP

Physiol Plantarum 176 (4) e14428 [2024-07-10; online 2024-07-10]

Chlorophyll is essential in photosynthesis, converting sunlight into chemical energy in plants, algae, and certain bacteria. Its structure, featuring a porphyrin ring enclosing a central magnesium ion, varies in forms like chlorophyll a, b, c, d, and f, allowing light absorption at a broader spectrum. With a 20-carbon phytyl tail (except for chlorophyll c), chlorophyll is anchored to proteins. Previous findings suggested the presence of chlorophyll with a modified farnesyl tail in thermophilic cyanobacteria Thermosynechoccocus vestitus. In our Arabidopsis thaliana PSII cryo-EM map, specific chlorophylls showed incomplete phytyl tails, suggesting potential farnesyl modifications. However, further high-resolution mass spectrometry (HRMS) analysis in A. thaliana and T. vestitus did not confirm the presence of any farnesyl tails. Instead, we propose the truncated tails in PSII models may result from binding pocket flexibility rather than actual modifications.

Swedish Metabolomics Centre (SMC) [Service]

PubMed 38981693

DOI 10.1111/ppl.14428

Crossref 10.1111/ppl.14428