FIG. 5.

Schematic representation of the various positions a DBF (A) or a DBD (B) molecule must occupy in the BphA active site relative to the activated dioxygen species for dioxygenation of the different vicinal carbons. The numbers of the atoms that would be attacked are indicated. The orientation of a biphenyl molecule (hatched), when dioxygenated at its major site, is shown for comparison. Note that for biphenyl the plane of the nonoxidized ring may rotate relative to the plane of the oxidized ring. DBF and DBD molecules in positions that are probably tolerated and lead to dioxygenations (see text) are shown shaded.