5v2c
From Proteopedia
RE-REFINEMENT OF CRYSTAL STRUCTURE OF PHOTOSYSTEM II COMPLEX
Structural highlights
FunctionPSBD_THEVL D1 (PsbA) and D2 (PsbD) bind P680, the primary electron donor of photosystem II (PSII) as well as electron acceptors. PSII is a light-driven water plastoquinone oxidoreductase, using light energy to abstract electrons from H(2)O, generating a proton gradient subsequently used for ATP formation. D2 is needed for assembly of a stable PSII complex.[HAMAP-Rule:MF_01383] Publication Abstract from PubMedPhotosystem 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 A 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. Chlorophyll a with a farnesyl tail in thermophilic cyanobacteria.,Wiwczar JM, LaFountain AM, Wang J, Frank HA, Brudvig GW Photosynth Res. 2017 Jul 24. doi: 10.1007/s11120-017-0425-4. PMID:28741056[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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