A catalytic active Michaelis-complex shows its secrets (July 2017)
In their paper published in Nature Communications, Tobias Werther and Holger Dobbek together with colleagues from the group of Peter Hildebrandt (Unicat, TU Berlin, Germany) used X-ray crystallography and resonance Raman spectroscopy to investigate the Michaelis complex of xenobiotic reductase A (reactive reduced cofactor bound to its substrates) and compare it to the non-reactive oxidized Michaelis complex mimics.
Tobias Werther and colleagues found that substrates bind in different orientations to the oxidized and reduced flavin, in both cases flattening its structure. But only authentic Michaelis complexes display an unexpected rich vibrational band pattern uncovering a strong donor–acceptor complex between reduced flavin and substrate. This interaction likely activates the catalytic ground state of the reduced flavin, accelerating the reaction within a compressed cofactor–substrate complex.
Citation:
T. Werther, S. Wahlefeld, J. Salewski, U. Kuhlmann, I. Zebger, P. Hilderbrandt and H. Dobbek (2017) Nature Communications, 8, 16084. DOI: 10.1038/ncomms16084