Two distinct but interchangeable mechanisms for flipping of lipid-linked oligosaccharides
| Autor: | Cristina Alaimo, Cristina L. Marolda, Ina Catrein, Miguel A. Valvano, Mario F. Feldman, Nico Callewaert, Markus Aebi, Laura Morf |
|---|---|
| Rok vydání: | 2006 |
| Předmět: |
Lipopolysaccharides
Glycosylation DNA Recombinant ATP-binding cassette transporter Article General Biochemistry Genetics and Molecular Biology Campylobacter jejuni chemistry.chemical_compound Bacterial Proteins Biosynthesis N-linked glycosylation Escherichia coli Molecular Biology chemistry.chemical_classification General Immunology and Microbiology biology Membrane transport protein Escherichia coli Proteins General Neuroscience Genetic Complementation Test Membrane Transport Proteins O Antigens Gene Expression Regulation Bacterial Flippase Oligosaccharide chemistry Membrane protein Biochemistry Mutation biology.protein ATP-Binding Cassette Transporters |
| Zdroj: | The EMBO Journal. 25:967-976 |
| ISSN: | 1460-2075 0261-4189 |
| DOI: | 10.1038/sj.emboj.7601024 |
| Popis: | Translocation of lipid-linked oligosaccharide (LLO) intermediates across membranes is an essential but poorly understood process in eukaryotic and bacterial glycosylation pathways. Membrane proteins defined as translocases or flippases are implicated to mediate the translocation reaction. The membrane protein Wzx has been proposed to mediate the translocation across the plasma membrane of lipopolysaccharide (LPS) O antigen subunits, which are assembled on an undecaprenyl pyrophosphate lipid carrier. Similarly, PglK (formerly WlaB) is a Campylobacter jejuni-encoded ABC-type transporter proposed to mediate the translocation of the undecaprenylpyrophosphate-linked heptasaccharide intermediate involved in the recently identified bacterial N-linked protein glycosylation pathway. A combination of genetic and carbohydrate structural analyses defined and characterized flippase activities in the C. jejuni N-linked protein glycosylation and the Escherichia coli LPS O antigen biosynthesis. PglK displayed relaxed substrate specificity with respect to the oligosaccharide structure of the LLO intermediate and complemented a wzx deficiency in E. coli O-antigen biosynthesis. Our experiments provide strong genetic evidence that LLO translocation across membranes can be catalyzed by two distinct proteins that do not share any sequence similarity. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Plný text