title: The C-terminal of rat 4-hydroxyphenylpyruvate dioxygenase is indispensable for enzyme activity.
abstract: 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 alpha-ketoisocaproate dioxygenase (alpha KICD) 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 alpha KICD activities. This finding suggests that the C-terminal extension domain plays an essential role in the catalytic activity of the enzyme.
authors.affiliation: Dyson Perrins Laboratory, University of Oxford, UK.
authors.forename: M H
authors.initials: MH
authors.lastname: Lee
authors.forename: Z H
authors.initials: ZH
authors.lastname: Zhang
authors.forename: C H
authors.initials: CH
authors.lastname: MacKinnon
authors.forename: J E
authors.initials: JE
authors.lastname: Baldwin
authors.forename: N P
authors.initials: NP
authors.lastname: Crouch
mesh_terms: D015111:4-Hydroxyphenylpyruvate Dioxygenase / Q000096:biosynthesis / Q000737:chemistry* / Q000378:metabolism*; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D003001:Cloning, Molecular; D018076:DNA, Complementary; D007519:Isoantigens / Q000096:biosynthesis / Q000737:chemistry / Q000378:metabolism; D007700:Kinetics; D008099:Liver / Q000201:enzymology; D051379:Mice; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D051381:Rats; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000378:metabolism; D017384:Sequence Deletion; D017386:Sequence Homology, Amino Acid; D012689:Sequence Homology, Nucleic Acid
chemical_list: D018076:DNA, Complementary; D007519:Isoantigens; D011994:Recombinant Proteins; C030497:liver specific F antigen; D015111:4-Hydroxyphenylpyruvate Dioxygenase