Identification of Phenylalanine 3-Hydroxylase for meta-Tyrosine Biosynthesis

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• 作者：Wenjun Zhang ; Brian D. Ames ; Christopher T. Walsh
• 刊名：Biochemistry
• 出版年：2011
• 出版时间：June 21, 2011
• 年：2011
• 卷：50
• 期：24
• 页码：5401-5403
• 全文大小：702K
• 年卷期：v.50,no.24(June 21, 2011)
• ISSN：1520-4995

文摘

Phenylalanine hydroxylase (PheH) is an iron(II)-dependent enzyme that catalyzes the hydroxylation of aromatic amino acid l-phenylalanine (l-Phe) to l-tyrosine (l-Tyr). The enzymatic modification has been demonstrated to be highly regiospecific, forming proteinogenic para-Tyr (p-Tyr) exclusively. Here we biochemically characterized the first example of a phenylalanine 3-hydroxylase (Phe3H) that catalyzes the synthesis of meta-Tyr (m-Tyr) from Phe. Subsequent mutagenesis studies revealed that two residues in the active site of Phe3H (Cys187 and Thr202) contribute to C-3 rather than C-4 hydroxylation of the phenyl ring. This work sets the stage for the mechanistic and structural study of regiospecific control of the substrate hydroxylation by PheH.