The C-terminal Domain of 4-Hydroxyphenylacetate 3-Hydroxylase from Acinetobacter baumannii Is an Autoinhibitory Domain

Background: The flavin reduction rate of C1 reductase is enhanced ∼20-fold upon binding to HPA (effector).Results: The truncated C1 variant lacking the C-terminal domain is reduced as fast as the wild-type enzyme in the presence of HPA.Conclusion: The C-terminal domain is an autoinhibitory domain.Significance: These findings demonstrate a novel principle that may be used in a wide variety of oxygenases.