N-terminal, non-catalytic, domain of BphC_JF8, (2,3-dihydroxybiphenyl 1,2-dioxygenase) from Bacillus sp. JF8, and similar proteins
2,3-dihydroxybiphenyl 1,2-dioxygenase (BphC) catalyzes the extradiol ring cleavage reaction of 2,3-dihydroxybiphenyl, a key step in the polychlorinated biphenyls (PCBs) degradation pathway (bph pathway). BphC belongs to the type I extradiol dioxygenase family, which requires a metal ion in the active site in its catalytic mechanism. Polychlorinated biphenyl degrading bacteria demonstrate a multiplicity of BphCs. This subfamily of BphC is represented by the enzyme purified from the thermophilic biphenyl and naphthalene degrader, Bacillus sp. JF8. The members in this family of BphC enzymes may use either Mn(II) or Fe(II) as cofactors. The enzyme purified from Bacillus sp. JF8 is Mn(II)-dependent, however, the enzyme from Rhodococcus jostii RHAI has Fe(II) bound to it. BphC_JF8 is thermostable and its optimum activity is at 85 degrees C. The enzymes in this family have an internal duplication. This family represents the N-terminal repeat.