2phm
From Proteopedia
STRUCTURE OF PHENYLALANINE HYDROXYLASE DEPHOSPHORYLATED
Overview
Phenylalanine hydroxylase converts phenylalanine to tyrosine, a rate-limiting step in phenylalanine catabolism and protein and neurotransmitter biosynthesis. It is tightly regulated by the substrates phenylalanine and tetrahydrobiopterin and by phosphorylation. We present the crystal structures of dephosphorylated and phosphorylated forms of a dimeric enzyme with catalytic and regulatory properties of the wild-type protein. The structures reveal a catalytic domain flexibly linked to a regulatory domain. The latter consists of an N-terminal autoregulatory sequence (containing Ser 16, which is the site of phosphorylation) that extends over the active site pocket, and an alpha-beta sandwich core that is, unexpectedly, structurally related to both pterin dehydratase and the regulatory domains of metabolic enzymes. Phosphorylation has no major structural effects in the absence of phenylalanine, suggesting that phenylalanine and phosphorylation act in concert to activate the enzyme through a combination of intrasteric and possibly allosteric mechanisms.
About this Structure
2PHM is a Single protein structure of sequence from Rattus norvegicus. Full crystallographic information is available from OCA.
Reference
Structural basis of autoregulation of phenylalanine hydroxylase., Kobe B, Jennings IG, House CM, Michell BJ, Goodwill KE, Santarsiero BD, Stevens RC, Cotton RG, Kemp BE, Nat Struct Biol. 1999 May;6(5):442-8. PMID:10331871 Page seeded by OCA on Sun May 4 13:07:43 2008
