Cloned (Comment) | Organism |
---|---|
gene msbA, overexpression of N-terminally His6-tagged enzyme in Escherichia coli | Escherichia coli |
Inhibitors | Comment | Organism | Structure |
---|---|---|---|
lipid A | translocation of NBD-phosphatidylethanolamine is inhibited by the presence of the putative physiological substrate lipid A, probably due to competition for flipping of 7-nitrobenz-2-oxa-1,3-diazole-labeled phosphoethanolamine (NBD-PE) | Escherichia coli |
Localization | Comment | Organism | GeneOntology No. | Textmining |
---|---|---|---|---|
membrane | - |
Escherichia coli | 16020 | - |
Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|
ATP + H2O + lipid A-core oligosaccharide[side 1] | Escherichia coli | - |
ADP + phosphate + lipid A-core oligosaccharide[side 2] | - |
? |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Escherichia coli | P60752 | - |
- |
Purification (Comment) | Organism |
---|---|
recombinant N-terminally His6-tagged enzyme from isolated Escherichia coli inside-out membrane vesicles by nickel affinity chromatography | Escherichia coli |
Renatured (Comment) | Organism |
---|---|
reconstitution of purified MsbA into proteoliposomes, method, overview | Escherichia coli |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
ATP + H2O + lipid A-core oligosaccharide[side 1] | - |
Escherichia coli | ADP + phosphate + lipid A-core oligosaccharide[side 2] | - |
? | |
ATP + H2O + phosphoethanolamine[side 1] | fluorescently NBD (7-nitrobenz-2-oxa-1,3-diazole)-labeled | Escherichia coli | ADP + phosphate + phosphoethanolamine[side 2] | - |
? | |
additional information | purified MsbA from Escherichia coli displays high ATPase activity, and binds to lipids and lipid-like molecules, including lipid A, with affinity in the low micromolar range. Purified MsbA is reconstituted into proteoliposomes of Escherichia coli lipid and shows ability to translocate 7-nitrobenz-2-oxa-1,3-diazole (NBD)-labeled lipid derivatives. In this system, the protein displays maximal lipid flippase activity of 7.7 nmol of lipid translocated per mg of protein over a 20 min period for an acyl chain-labeled phosphatidylethanolamine derivative. Lipid flippase activity requires ATP hydrolysis, and is dependent on the concentration of ATP and NBD-lipid. MsbA can accommodate lipids with bulky carbohydrate headgroups | Escherichia coli | ? | - |
? |
Subunits | Comment | Organism |
---|---|---|
homodimer | - |
Escherichia coli |
Synonyms | Comment | Organism |
---|---|---|
lipid flippase | - |
Escherichia coli |
MsbA | - |
Escherichia coli |
Temperature Optimum [°C] | Temperature Optimum Maximum [°C] | Comment | Organism |
---|---|---|---|
37 | - |
assay at | Escherichia coli |
pH Optimum Minimum | pH Optimum Maximum | Comment | Organism |
---|---|---|---|
7.5 | - |
assay at | Escherichia coli |
General Information | Comment | Organism |
---|---|---|
evolution | the MsbA protein is an essential ABC (ATP-binding-cassette) superfamily member in Gram-negative bacteria | Escherichia coli |
additional information | reconstitution of purified MsbA into proteoliposomes, method, overview | Escherichia coli |
physiological function | the homodimeric ATP-dependent lipid translocase or flippase transports lipid A from the inner to the outer leaflet of the cytoplasmic membrane | Escherichia coli |