4OYL: Humicola insolens cutinase in complex with mono-ethylphosphate

The interaction of lipolytic enzymes with anionic surfactants is of great interest with respect to industrially produced detergents. Here, we report the interaction of cutinase from the thermophilic fungus Humicola insolens with the anionic surfactant SDS, and show the enzyme specifically binds a single SDS molecule under nondenaturing concentrations. Protein interaction with SDS was investigated by NMR, ITC and molecular dynamics simulations. The NMR resonances of the protein were assigned, with large stretches of the protein molecule not showing any detectable resonances. SDS is shown to specifically interact with the loops surrounding the catalytic triad with medium affinity (Ka approximately 10(5) M(-1) ). The mode of binding is closely similar to that seen previously for binding of amphiphilic molecules and substrate analogues to cutinases, and hence SDS acts as a substrate mimic. In addition, the structure of the enzyme has been solved by X-ray crystallography in its apo form and after cocrystallization with diethyl p-nitrophenyl phosphate (DNPP) leading to a complex with monoethylphosphate (MEP) esterified to the catalytically active serine. The enzyme has the same fold as reported for other cutinases but, unexpectedly, esterification of the active site serine is accompanied by the ethylation of the active site histidine which flips out from its usual position in the triad.
PDB ID: 4OYLDownload
MMDB ID: 121015
PDB Deposition Date: 2014/2/12
Updated in MMDB: 2017/12
Experimental Method:
x-ray diffraction
Resolution: 2.05  Å
Source Organism:
Similar Structures:
Biological Unit for 4OYL: monomeric; determined by author
Molecular Components in 4OYL
Label Count Molecule
Protein (1 molecule)
Molecule annotation
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Citing MMDB