Imbalance in tetrapyrrole metabolites caused by deletion of scp genes in the cyanobacterium Synechocystis sp. PCC 6803 results in dramatic cellular effects

• Light-harvsting like (Lil) proteins contain a chlorophyll-binding domain similar to the chlorophyll a/b binding antenna proteins of plants. The five small Cab-like proteins (SCPs) of the cyanobacterium Synechocystis sp. PCC 6803 belong to the Lil family. They have been shown to stabilize chlorophyll and to play a role in the tetrapyrrole biosynthesis pathway (Xu, H., Vavilin, D., Funk, C. and Vermaas, W. (2004) J. Biol. Chem. 279, 27971-27979). Here we show that deletion of the five scp genes in a PSI-less mutant results in a decrease of Photosystem II amount in the thylakoid membrane. This reduction of Photosystem II leads to increased cell volume, disorganized thylakoid membranes in the cell, and metabolic imbalance. We conclude that the lack of SCPs alters the assembly/repair of Photosystem II, causing an imbalance in the energetic level of the mutant cells.

Subject headings

NATURVETENSKAP  -- Biologi -- Biokemi och molekylärbiologi (hsv//swe)

NATURAL SCIENCES  -- Biological Sciences -- Biochemistry and Molecular Biology (hsv//eng)

Keyword

Photosynthesis

Photosystem II

chlorophyll-binding proteins

tetrapyrrole biosynthesis

photodamage

non-photochemical quenching

SCPs

LHCII

Molecular biology

Molekylärbiologi

Biochemistry

Biokemi

biokemi

Biochemistry

Publication and Content Type

vet (subject category)

ovr (subject category)