PMID:15175282
| Citation |
Lequette, Y, Odberg-Ferragut, C, Bohin, JP and Lacroix, JM (2004) Identification of mdoD, an mdoG paralog which encodes a twin-arginine-dependent periplasmic protein that controls osmoregulated periplasmic glucan backbone structures. J. Bacteriol. 186:3695-702 |
|---|---|
| Abstract |
Osmoregulated periplasmic glucans (OPGs) of Escherichia coli are anionic and highly branched oligosaccharides that accumulate in the periplasmic space in response to low osmolarity of the medium. The glucan length, ranging from 5 to 12 glucose residues, is under strict control. Two genes that form an operon, mdoGH, govern glucose backbone synthesis. The new gene mdoD, which appears to be a paralog of mdoG, was characterized in this study. Cassette inactivation of mdoD resulted in production of OPGs with a higher degree of polymerization, indicating that OpgD, the mdoD product (according to the new nomenclature), controls the glucose backbone structures. OpgD secretion depends on the Tat secretory pathway. Orthologs of the mdoG and mdoD genes are found in various proteobacteria. Most of the OpgD orthologs exhibit a Tat-dependent secretion signal, while most of the OpgG orthologs are Sec dependent. |
| Links |
PubMed PMC419940 Online version:10.1128/JB.186.12.3695-3702.2004 |
| Keywords |
Amino Acid Sequence; Escherichia coli/genetics; Escherichia coli/metabolism; Escherichia coli Proteins/chemistry; Escherichia coli Proteins/genetics; Escherichia coli Proteins/metabolism; Gene Expression Regulation, Bacterial; Glucans/biosynthesis; Membrane Transport Proteins/genetics; Membrane Transport Proteins/metabolism; Molecular Sequence Data; Mutation; Osmolar Concentration; Periplasm/metabolism; Periplasmic Proteins/chemistry; Periplasmic Proteins/genetics; Periplasmic Proteins/metabolism |
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Significance
This paper compared that glucan backbones were altered in a mdoD mutant compared to the isogenic control. It also found that the protein has a TAT signal peptide and apparently the second arginine residue of the three total found in the peptide is critical to the translocation process.
Useful Materials and Methods
The authors removed all the OPG substituents and performed Mass Spec on the glycan backbones. They also used chromotography to separate the different species.
Annotations
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