Abstract
Photosystem II (PSII) of oxygenic photosynthetic organisms normally contains exclusively chlorophyll a (Chl a) as its major light-harvesting pigment. Chl a canonically consists of the chlorin headgroup with a 20-carbon, 4-isoprene unit, phytyl tail. We have examined the 1.9 Å crystal structure of PSII from thermophilic cyanobacteria reported by Shen and coworkers in 2012 (PDB accession of 3ARC/3WU2). A newly refined electron density map from this structure, presented here, reveals that some assignments of the cofactors may be different from those modeled in the 3ARC/3WU2 structure, including a specific Chl a that appears to have a truncated tail by one isoprene unit. We provide experimental evidence using high-performance liquid chromatography and mass spectrometry for a small population of Chl a esterified to a 15-carbon farnesyl tail in PSII of thermophilic cyanobacteria.
Original language | English |
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Pages (from-to) | 175-182 |
Number of pages | 8 |
Journal | Photosynthesis Research |
Volume | 134 |
Issue number | 2 |
DOIs | |
Publication status | Published - Nov 1 2017 |
Keywords
- CP43
- Chlorophyll a
- Photosystem II
- Thermosynechococcus elongatus
- X-ray crystal structure
ASJC Scopus subject areas
- Biochemistry
- Plant Science
- Cell Biology