Abstract
Diacylglycerol kinase (DgkA) catalyzes the ATP-dependent phosphorylation of diacylglycerol to phosphatidic acid for use in shuttling water-soluble components to membrane derived oligosaccharide and lipopolysaccharide in the cell envelope of Gram-negative bacteria1. For half a century, this 121-residue kinase has served as a paradigm for investigating membrane protein enzymology1,3-7, folding8,9, assembly10-13, and stability1,14. Here, we present crystal structures for three functional forms of this unique and paradigmatic kinase, one of which is wild type (WT). These reveal a homo-trimeric enzyme with three transmembrane helices and an N-terminal amphiphilic helix per monomer. Bound lipid substrate and docked ATP identify the putative active site which is of the composite, shared site type. The crystal structures rationalize extensive biochemical and biophysical data on the enzyme. They are however at variance with a published solution NMR model2 in that domain swapping, a key feature of the solution form, is not observed in the crystal structures.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.