title: Atomic picture of ligand migration in toluene 4-monooxygenase.
abstract: Computational modeling combined with mutational and activity assays was used to underline the substrate migration pathways in toluene 4-monooxygenase, a member of the important family of bacterial multicomponent monooxygenases (BMMs). In all structurally defined BMM hydroxylases, several hydrophobic cavities in the α-subunit map a preserved path from the protein surface to the diiron active site. Our results confirm the presence of two pathways by which different aromatic molecules can enter/escape the active site. While the substrate is observed to enter from both channels, the more hydrophilic product is withdrawn mainly from the shorter channel ending at residues D285 and E214. The long channel ends in the vicinity of S395, whose variants have been seen to affect activity and specificity. These mutational effects are clearly reproduced and rationalized by the in silico studies. Furthermore, the combined computational and experimental results highlight the importance of residue F269, which is located at the intersection of the two channels.
authors.affiliation: Department of Life Sciences, Barcelona Supercomputing Center , Nexus II Building, 08034 Barcelona, Spain.
authors.forename: Ali
authors.initials: A
authors.lastname: Hosseini
authors.forename: Moran
authors.initials: M
authors.lastname: Brouk
authors.forename: Maria Fatima
authors.initials: MF
authors.lastname: Lucas
authors.forename: Fabian
authors.initials: F
authors.lastname: Glaser
authors.forename: Ayelet
authors.initials: A
authors.lastname: Fishman
authors.forename: Victor
authors.initials: V
authors.lastname: Guallar
mesh_terms: D020134:Catalytic Domain; D004926:Escherichia coli / Q000201:enzymology; D057927:Hydrophobic and Hydrophilic Interactions; D008024:Ligands; D008958:Models, Molecular; D009068:Movement; D010105:Oxygenases / Q000737:chemistry* / Q000378:metabolism*
chemical_list: D008024:Ligands; D010105:Oxygenases; C068610:toluene-4-monooxygenase