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Expression of Cds4/5 of Arabidopsis chloroplasts in E. coli reveals the membrane topology of the C‐terminal region of CDP‐diacylglycerol synthases
Author(s) -
Sekiya Yusei,
Sawasato Katsuhiro,
Nishiyama Kenichi
Publication year - 2021
Publication title -
genes to cells
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.912
H-Index - 115
eISSN - 1365-2443
pISSN - 1356-9597
DOI - 10.1111/gtc.12880
Subject(s) - biology , diacylglycerol kinase , transmembrane protein , arabidopsis , chloroplast , transmembrane domain , biochemistry , membrane topology , biosynthesis , cytoplasm , cytosol , glycolipid , function (biology) , microbiology and biotechnology , membrane , gene , receptor , signal transduction , enzyme , mutant , protein kinase c
CDP‐diacylglycerol synthases (Cds) are conserved from bacteria to eukaryotes. Bacterial CdsA is involved not only in phospholipid biosynthesis but also in biosynthesis of glycolipid MPIase, an essential glycolipid that catalyzes membrane protein integration. We found that both Cds4 and Cds5 of Arabidopsis chloroplasts complement cdsA knockout by supporting both phospholipid and MPIase biosyntheses. Comparison of the sequences of CdsA and Cds4/5 suggests a difference in membrane topology at the C‐termini, since the region assigned as the last transmembrane region of CdsA, which follows the conserved cytoplasmic domain, is missing in Cds4/5. Deletion of the C‐terminal region abolished the function, indicating the importance of the region. Both 6 × His tag attachment to CdsA and substitution of the C‐terminal 6 residues with 6 × His did not affect the function. These 6 × His tags were sensitive to protease added from the cytosolic side in vitro, indicating that this region is not a transmembrane one but forms a membrane‐embedded reentrant loop. Thus, the C‐terminal region of Cds homologues forms a reentrant loop, of which structure is important for the Cds function.