Characterization of 4-hydroxyphenylpyruvate dioxygenase. Primary structure of the Pseudomonas enzyme.
The primary structure of Pseudomonas 4-hydroxyphenylpyruvate dioxygenase was determined. Sequence degradation of the intact protein and of peptides from three different digests of the carboxymethylated protein established a 357-residue polypeptide chain with a free alpha-amino group. Hydroxylamine cleavage at a single Asn-Gly sequence was useful. Comparisons with known structures in data banks revealed no close relationship with other characterized proteins. The human enzyme has a related composition, suggesting that also the eukaryotic form belongs to this protein type, but with a blocked N-terminus like in many other eukaryotic intracellular proteins. Secondary structure predictions suggest an alpha/beta mixed structure, fairly typical of globular proteins, without long segments of hydrophobicity or charge, although a region in the middle of the C-terminal third of the subunit appears to have the most extreme properties. A ferric centre, correlating with enzyme activity and absorbance at 595 nm, has previously been assigned to tyrosinate coordination. The Tyr and His distributions, and the position of a single Cys residue, all suggest a few likely sites, outside the C-terminal segment, for this centre.
Rüetschi
U
U
Department of Clinical Chemistry, Gothenburg, University, Sahlgren's Hospital, Sweden.
Odelhög
B
B
Lindstedt
S
S
Barros-Söderling
J
J
Persson
B
B
Jörnvall
H
H
D015111:4-Hydroxyphenylpyruvate Dioxygenase / Q000737:chemistry*; D000595:Amino Acid Sequence; D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D003488:Cyanogen Bromide; D006801:Humans; D019811:Hydroxylamine; D006898:Hydroxylamines; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000302:isolation & purification; D011487:Protein Conformation; D011549:Pseudomonas / Q000201:enzymology*; D014357:Trypsin
D006898:Hydroxylamines; D010446:Peptide Fragments; D019811:Hydroxylamine; D015111:4-Hydroxyphenylpyruvate Dioxygenase; D014357:Trypsin; D003488:Cyanogen Bromide