Hoffmann, R. A wiki for the life sciences where authorship matters. Nature Genetics (2008)

Editor

Personal info

View

About

Terms

Javascript disabled

Please enable Javascript support in your browser to use this application.

Instructions on how to enable JavaScript on different browsers can be found here: http://www.google.com/support/bin/answer.py?answer=23852.

[edit this page]

Ray, B.L. et al.

The biosynthesis of gram-negative endotoxin. A novel kinase in Escherichia coli membranes that incorporates the 4'-phosphate of lipid A.

Extracts of Escherichia coli contain an enzyme that generates the beta,1----6 linkage of lipid A from fatty-acylated monosaccharide precursors, according to the reaction: 2,3-diacyl-GlcN-1-P + UDP-2,3-diacyl-GlcN----2,3-diacyl-GlcN (beta, 1----6)2,3-diacyl-GlcN-1-P + UDP (Ray, B. L., Painter, G., and Raetz, C. R. H. (1984) J. Biol. Chem. 259, 4852-4859). We now describe a membrane-bound kinase that phosphorylates the 4'-position of the above tetraacyldisaccharide 1-phosphate product. The lipid A 4'-kinase is distinct from the diglyceride kinase of E. coli. When crude membrane preparations are employed, several nucleoside triphosphates are able to support the phosphorylation of the tetraacyldisaccharide 1-phosphate, but ATP is the most efficient. The 4'-kinase requires Mg2+ and is stimulated by phospholipids, especially cardiolipin. Under optimal conditions the specific activity in crude extracts is 0.5 nmol/min/mg. The enzyme is rapidly inactivated by preincubation in the presence of detergents, such as Nonidet P-40 or octylglucoside, but phosphoenolpyruvate and glycerol stabilize the enzyme. The product generated in vitro has been characterized by fast atom bombardment mass spectrometry and by 1H and 31P NMR spectroscopy. Those analyses confirm that the 4' hydroxyl is the site of phosphorylation. The 4'-kinase reported here is likely to represent a key step in the de novo biosynthesis of lipid A.[1]

References

The biosynthesis of gram-negative endotoxin. A novel kinase in Escherichia coli membranes that incorporates the 4'-phosphate of lipid A. Ray, B.L., Raetz, C.R. J. Biol. Chem. (1987) [Pubmed]

Annotations and hyperlinks in this abstract are from individual authors of WikiGenes or automatically generated by the WikiGenes Data Mining Engine. The abstract is from MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.About WikiGenes Open Access Licence Privacy Policy Terms of Use apsburg

The world's first wiki where authorship really matters (Nature Genetics, 2008). Due credit and reputation for authors. Imagine a global collaborative knowledge base for original thoughts. Search thousands of articles and collaborate with scientists around the globe.