Regulation and crystallization of phosphorylated and dephosphorylated forms of truncated dimeric phenylalanine hydroxylase.
Phenylalanine hydroxylase is regulated in a complex manner, including activation by phosphorylation. It is normally found as an equilibrium of dimeric and tetrameric species, with the tetramer thought to be the active form. We converted the protein to the dimeric form by deleting the C-terminal 24 residues and show that the truncated protein remains active and regulated by phosphorylation. This indicates that changes in the tetrameric quaternary structure of phenylalanine hydroxylase are not required for enzyme activation. Truncation also facilitates crystallization of both phosphorylated and dephosphorylated forms of the enzyme.
Kobe
B
B
St. Vincent's Institute of Medical Research, Fitzroy, Victoria, Australia. b.kobe@medicine_stvin.unimelb.edu.au
Jennings
I G
IG
House
C M
CM
Feil
S C
SC
Michell
B J
BJ
Tiganis
T
T
Parker
M W
MW
Cotton
R G
RG
Kemp
B E
BE
D000818:Animals; D016367:Baculoviridae / Q000235:genetics; D018360:Crystallography, X-Ray; D019281:Dimerization; D004789:Enzyme Activation; D006801:Humans; D013058:Mass Spectrometry; D010446:Peptide Fragments / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D010651:Phenylalanine Hydroxylase / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D010661:Phenylketonurias / Q000209:etiology; D010750:Phosphoproteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D010766:Phosphorylation; D011487:Protein Conformation; D051381:Rats; D011994:Recombinant Proteins / Q000737:chemistry; D017384:Sequence Deletion; D018411:Spodoptera / Q000166:cytology
D010446:Peptide Fragments; D010750:Phosphoproteins; D011994:Recombinant Proteins; D010651:Phenylalanine Hydroxylase