1tdw: Difference between revisions

From Proteopedia
Jump to navigation Jump to search
No edit summary
No edit summary
Line 1: Line 1:
[[Image:1tdw.jpg|left|200px]]
{{Seed}}
[[Image:1tdw.png|left|200px]]


<!--
<!--
Line 9: Line 10:
{{STRUCTURE_1tdw|  PDB=1tdw  |  SCENE=  }}  
{{STRUCTURE_1tdw|  PDB=1tdw  |  SCENE=  }}  


'''Crystal structure of double truncated human phenylalanine hydroxylase BH4-responsive PKU mutant A313T.'''
===Crystal structure of double truncated human phenylalanine hydroxylase BH4-responsive PKU mutant A313T.===




==Overview==
<!--  
Phenylketonuria patients harboring a subset of phenylalanine hydroxylase (PAH) mutations have recently shown normalization of blood phenylalanine levels upon oral administration of the PAH cofactor tetrahydrobiopterin [(6R)-L-erythro-5,6,7,8-tetrahydrobiopterin (BH4)]. Several hypotheses have been put forward to explain BH4 responsiveness, but the molecular basis for the corrective effect(s) of BH4 has not been understood. We have investigated the biochemical, kinetic, and structural changes associated with BH4-responsive mutations (F39L, I65T, R68S, H170D, E178G, V190A, R261Q, A300S, L308F, A313T, A373T, V388M, E390G, P407S, and Y414C). The biochemical and kinetic characterization of the 15 mutants studied points toward a multifactorial basis for the BH4 responsiveness; the mutants show residual activity (&gt;30% of WT) and display various kinetic defects, including increased Km (BH4) and reduced cooperativity of substrate binding, but no decoupling of cofactor (BH4) oxidation. For some, BH4 seems to function through stabilization and protection of the enzyme from inactivation and proteolytic degradation. In the crystal structures of a phenylketonuria mutant, A313T, minor changes were seen when compared with the WT PAH structures, consistent with the mild effects the mutant has upon activity of the enzyme both in vitro and in vivo. Truncations made in the A313T mutant PAH form revealed that the N and C termini of the enzyme influence active site binding. Of fundamental importance is the observation that BH4 appears to increase Phe catabolism if at least one of the two heterozygous mutations has any residual activity remaining.
The line below this paragraph, {{ABSTRACT_PUBMED_15557004}}, adds the Publication Abstract to the page
(as it appears on PubMed at http://www.pubmed.gov), where 15557004 is the PubMed ID number.
-->
{{ABSTRACT_PUBMED_15557004}}


==Disease==
==Disease==
Line 41: Line 45:
[[Category: Ugarte, M.]]
[[Category: Ugarte, M.]]
[[Category: Phenylalanine catabolism]]
[[Category: Phenylalanine catabolism]]
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sat May  3 09:50:09 2008''
 
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Tue Jul 29 08:09:40 2008''

Revision as of 08:09, 29 July 2008

File:1tdw.png

Template:STRUCTURE 1tdw

Crystal structure of double truncated human phenylalanine hydroxylase BH4-responsive PKU mutant A313T.Crystal structure of double truncated human phenylalanine hydroxylase BH4-responsive PKU mutant A313T.

Template:ABSTRACT PUBMED 15557004

DiseaseDisease

Known disease associated with this structure: Phenylketonuria OMIM:[261600], Hyperphenylalaninemia, mild OMIM:[261600]

About this StructureAbout this Structure

1TDW is a Single protein structure of sequence from Homo sapiens. Full crystallographic information is available from OCA.

ReferenceReference

Correction of kinetic and stability defects by tetrahydrobiopterin in phenylketonuria patients with certain phenylalanine hydroxylase mutations., Erlandsen H, Pey AL, Gamez A, Perez B, Desviat LR, Aguado C, Koch R, Surendran S, Tyring S, Matalon R, Scriver CR, Ugarte M, Martinez A, Stevens RC, Proc Natl Acad Sci U S A. 2004 Nov 30;101(48):16903-8. Epub 2004 Nov 19. PMID:15557004

Page seeded by OCA on Tue Jul 29 08:09:40 2008

Proteopedia Page Contributors and Editors (what is this?)Proteopedia Page Contributors and Editors (what is this?)

OCA