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The C‐terminal of rat 4‐hydroxyphenylpyruvate dioxygenase is indispensable for enzyme activity
Author(s) -
Lee Meng-Huee,
Zhang Zhi-Hong,
MacKin Colin H.,
Baldwin Jack E.,
Crouch Nicholas P.
Publication year - 1996
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(96)00902-7
Subject(s) - dioxygenase , enzyme , biochemistry , escherichia coli , site directed mutagenesis , mutagenesis , chemistry , mutant , enzyme assay , biology , microbiology and biotechnology , gene
We have cloned and overexpressed rat 4‐hydroxyphenylpyruvate dioxygenase (4HPPD) in Escherichia coli . The soluble, active recombinant enzyme was shown to contain both 4HPPD and α‐ketoisocaproate dioxygenase (αKICD) activity. However, upon truncation of the 14 amino acids at the C‐terminus by site‐directed mutagenesis, the resulting mutant enzyme (rat F antigen) exhibited complete loss of 4HPPD and αKICD activities. This finding suggests that the C‐terminal extension domain plays an essential role in the catalytic activity of the enzyme.