Membrane protein insertion: mixing eukaryotic and prokaryotic concepts.
Proteins are translocated across or inserted into membranes by machines that are composed of soluble and membrane-anchored subunits. The molecular action of these machines and their evolutionary origin are at present the focus of intense research. For instance, our understanding of the mode of insertion of beta-barrel membrane proteins into the outer membrane of endosymbiotically derived organelles has increased rapidly during the past few years. In particular, the identification of the Omp85/YaeT-involving pathways in Neisseria meningitidis, Escherichia coli and cyanobacteria, and homologues of Omp85/YaeT in chloroplasts and mitochondria, has provided new clues about the ancestral beta-barrel protein insertion pathway. This review focuses on recent advances in the elucidation of the evolutionarily conserved concepts that underlie the translocation and insertion of beta-barrel membrane proteins.
Schleiff
Enrico
E
Department of Biology I, Ludwig-Maximilians-Universität Munich, Menzinger Strasse 67, 80638 Munich, Germany. schleiff@lrz.uni-muenchen.de
Soll
Jürgen
J
D000818:Animals; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000378:metabolism; D001419:Bacteria; D001425:Bacterial Outer Membrane Proteins / Q000737:chemistry / Q000378:metabolism; D002352:Carrier Proteins / Q000737:chemistry / Q000378:metabolism; D002736:Chloroplasts / Q000378:metabolism*; D005057:Eukaryotic Cells / Q000378:metabolism*; D006801:Humans; D008565:Membrane Proteins / Q000737:chemistry / Q000378:metabolism*; D008928:Mitochondria / Q000378:metabolism; D000090622:Mitochondrial Precursor Protein Import Complex Proteins; D010944:Plants; D011387:Prokaryotic Cells / Q000378:metabolism*; D011498:Protein Precursors / Q000737:chemistry / Q000378:metabolism; D021381:Protein Transport
D029681:Arabidopsis Proteins; D001425:Bacterial Outer Membrane Proteins; D002352:Carrier Proteins; D008565:Membrane Proteins; D000090622:Mitochondrial Precursor Protein Import Complex Proteins; C115176:Omp85 protein, Neisseria; D011498:Protein Precursors; C491244:TOC75 protein, Arabidopsis