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Photosystem II complex in vivo is a monomer.

ABSTRACT: Photosystem II (PS II) complexes are membrane protein complexes that are composed of >20 distinct subunit proteins. Similar to many other membrane protein complexes, two PS II complexes are believed to form a homo-dimer whose molecular mass is approximately 650 kDa. Contrary to this well known concept, we propose that the functional form of PS II in vivo is a monomer, based on the following observations. Deprivation of lipids caused the conversion of PS II from a monomeric form to a dimeric form. Only a monomeric PS II was detected in solubilized cyanobacterial and red algal thylakoids using blue-native polyacrylamide gel electrophoresis. Furthermore, energy transfer between PS II units, which was observed in the purified dimeric PS II, was not detected in vivo. Our proposal will lead to a re-evaluation of many crystallographic models of membrane protein complexes in terms of their oligomerization status.

SUBMITTER: Takahashi T

PROVIDER: S-EPMC2708856 | biostudies-other | 2009 Jun

REPOSITORIES: biostudies-other

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Photosystem II complex in vivo is a monomer.

Takahashi Takeshi T Inoue-Kashino Natsuko N Ozawa Shin-Ichiro S Takahashi Yuichiro Y Kashino Yasuhiro Y Satoh Kazuhiko K

The Journal of biological chemistry 20090407 23

Photosystem II (PS II) complexes are membrane protein complexes that are composed of >20 distinct subunit proteins. Similar to many other membrane protein complexes, two PS II complexes are believed to form a homo-dimer whose molecular mass is approximately 650 kDa. Contrary to this well known concept, we propose that the functional form of PS II in vivo is a monomer, based on the following observations. Deprivation of lipids caused the conversion of PS II from a monomeric form to a dimeric form ...[more]

PMID: 19351885

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