@article {1160,
	title = {Molecular basis for metabolite channeling in a ring opening enzyme of the phenylacetate degradation pathway [National Cryo-Electron Microscopy Facility (INT)]},
	journal = {Nature Communications},
	volume = {10},
	year = {2019},
	month = {09, 2019},
	type = {Article},
	chapter = {4127},
	abstract = {Substrate channeling is a mechanism for the internal transfer of hydrophobic, unstable or toxic intermediates from the active site of one enzyme to another. Such transfer has previously been described to be mediated by a hydrophobic tunnel, the use of electrostatic highways or pivoting and by conformational changes. The enzyme PaaZ is used by many bacteria to degrade environmental pollutants. PaaZ is a bifunctional enzyme that catalyzes the ring opening of oxepin-CoA and converts it to 3-oxo-5,6-dehydrosuberyl-CoA. Here we report the structures of PaaZ determined by electron cryomicroscopy with and without bound ligands. The structures reveal that three domain-swapped dimers of the enzyme form a trilobed structure. A combination of small-angle X-ray scattering (SAXS), computational studies, mutagenesis and microbial growth experiments suggests that the key intermediate is transferred from one active site to the other by a mechanism of electrostatic pivoting of the CoA moiety, mediated by a set of conserved positively charged residues.},
	keywords = {Bacterial structural biology, Cryoelectron microscopy, Multienzyme complexes},
	author = {Nitish Sathyanarayanan and Giuseppe Cannone and Lokesh Gakhar and Nainesh Katagihallimath and Ramanathan Sowdhamini and Subramanian Ramaswamy and Kutti R. Vinothkumar}
}
