A three-dimensional model of the PsbS protein was built with the help of homology-modeling methods. This protein is also known as CP22 and is associated with the protection of photosystem II of thylakoid from excess quanta of light energy absorbed by the photosynthetic apparatus. PsbS is reported to bind two molecules of zeaxanthin at low pH (<5.0) and is believed to be essential for rapid nonphotochemical quenching (qE) of chlorophyll a fluorescence in photosystem II. An attempt was made to explain the pH modulation of the conformation of protein through salt-bridges Glu(-)(122)-Lys(+)(113) and Glu(-)(226)-Lys(+)(217). Binding of two molecules of zeaxanthin in the three-dimensional model of PsbS is postulated. The molecular mechanism of photoprotection by PsbS is explained through the model.
Three-dimensional model of zeaxanthin binding PsbS protein associated with nonphotochemical quenching of excess quanta of light energy absorbed by the photosynthetic apparatus.,Haripal PK, Raval HK, Raval MK, Rawal RM, Biswal B, Biswal UC J Mol Model. 2006 Sep;12(6):847-53. Epub 2006 Mar 15. PMID:16538483[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
↑ Haripal PK, Raval HK, Raval MK, Rawal RM, Biswal B, Biswal UC. Three-dimensional model of zeaxanthin binding PsbS protein associated with nonphotochemical quenching of excess quanta of light energy absorbed by the photosynthetic apparatus. J Mol Model. 2006 Sep;12(6):847-53. Epub 2006 Mar 15. PMID:16538483 doi:10.1007/s00894-006-0103-5
