Episodic positive selection during the evolution of naphthalene dioxygenase to nitroarene dioxygenase

摘要: Using different maximum-likelihood models of adaptive evolution, signatures natural selective pressure, operating across the naphthalene family dioxygenases, were examined. A lineage- and branch-site specific combined analysis revealed that purifying selection pressure dominated evolutionary history enzyme family. Specifically, episodic positive Darwinian affecting only a few sites in subset lineages, was found to be responsible for evolution nitroarene dioxygenases (NArDO) from dioxygenase (NDO). Site-specific confirmed absence diversifying at any particular site. Different sets positively selected residues, obtained analysis, detected each NArDO. They mainly located around active site, catalytic pocket their adjacent regions, when mapped onto 3D structure α-subunit NDO. The present enriches current understanding also broadens scope rational alteration substrate specificity by directed evolution.