4-hydroxyphenylacetate 3-hydroxylase C terminal
HpaB encodes part of the 4-hydroxyphenylacetate 3-hydroxylase from Escherichia coli. HpaB is part of a heterodimeric enzyme that also requires HpaC. The enzyme is NADH-dependent and uses FAD as the redox chromophore. This family also includes PvcC may play a role in one of the proposed hydroxylation steps of pyoverdine chromophore biosynthesis.