Phenylalanine meta-Hydroxylase: A Single Residue Mediates Mechanistic Control of Aromatic Amino Acid Hydroxylation.

ABSTRACT: The rare nonproteinogenic amino acid, meta-l-tyrosine is biosynthetically intriguing. Whilst the biogenesis of tyrosine from phenylalanine is well characterised, the mechanistic basis for meta-hydroxylation is unknown. Herein, we report the analysis of 3-hydroxylase (Phe3H) from Streptomyces coeruleorubidus. Insights from kinetic analyses of the wild-type enzyme and key mutants as well as of the biocatalytic conversion of synthetic isotopically labelled substrates and fluorinated substrate analogues advance understanding of the process by which meta-hydroxylation is mediated, revealing T202 to play an important role. In the case of the WT enzyme, a deuterium label at the 3-position is lost, whereas in in the T202A mutant 75 % retention is observed, with loss of stereospecificity. These dat

SUBMITTER: Gruschow S 

PROVIDER: S-EPMC7027792 | biostudies-literature | 2020 Feb

REPOSITORIES: biostudies-literature