Structure-function analysis of phytanoyl-CoA 2-hydroxylase mutations causing Refsum's disease.
Refsum's disease is a neurological syndrome characterized by adult-onset retinitis pigmentosa, anosmia, sensory neuropathy and phytanic acidaemia. Many cases are caused by mutations in peroxisomal oxygenase phytanoyl-CoA 2-hydroxylase (PAHX) which catalyses the initial alpha-oxidation step in t...
Main Authors: | , , , , , , |
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Format: | Journal article |
Language: | English |
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2001
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author | Mukherji, M Chien, W Kershaw, N Clifton, I Schofield, C Wierzbicki, A Lloyd, MD |
author_facet | Mukherji, M Chien, W Kershaw, N Clifton, I Schofield, C Wierzbicki, A Lloyd, MD |
author_sort | Mukherji, M |
collection | OXFORD |
description | Refsum's disease is a neurological syndrome characterized by adult-onset retinitis pigmentosa, anosmia, sensory neuropathy and phytanic acidaemia. Many cases are caused by mutations in peroxisomal oxygenase phytanoyl-CoA 2-hydroxylase (PAHX) which catalyses the initial alpha-oxidation step in the degradation of phytanic acid. Both pro and mature forms of recombinant PAHX were produced in Escherichia coli, highly purified, and shown to have a requirement for iron(II) as a co-factor and 2-oxoglutarate as a co-substrate. Sequence analysis in the light of crystallographic data for other members of the 2-oxoglutarate-dependent oxygenase super-family led to secondary structural predictions for PAHX, which were tested by site-directed mutagenesis. The H175A and D177A mutants did not catalyse hydroxylation of phytanoyl-CoA, consistent with their assigned role as iron(II) binding ligands. The clinically observed P29S, Q176K, G204S, N269H, R275Q and R275W mutants were assayed for both 2-oxoglutarate and phytanoyl-CoA oxidation. The P29S mutant was fully active, implying that the mutation resulted in defective targeting of the protein to peroxisomes. Mutation of Arg-275 resulted in impaired 2-oxoglutarate binding. The Q176K, G204S and N269H mutations caused partial uncoupling of 2-oxoglutarate conversion from phytanoyl-CoA oxidation. The results demonstrate that the diagnosis of Refsum's disease should not solely rely upon PAHX assays for 2-oxoglutarate or phytanoyl-CoA oxidation. |
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format | Journal article |
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institution | University of Oxford |
language | English |
last_indexed | 2024-03-07T06:22:41Z |
publishDate | 2001 |
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spelling | oxford-uuid:f336b6f4-f1fe-45ba-b901-31bf49fcb2802022-03-27T12:10:22ZStructure-function analysis of phytanoyl-CoA 2-hydroxylase mutations causing Refsum's disease.Journal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:f336b6f4-f1fe-45ba-b901-31bf49fcb280EnglishSymplectic Elements at Oxford2001Mukherji, MChien, WKershaw, NClifton, ISchofield, CWierzbicki, ALloyd, MDRefsum's disease is a neurological syndrome characterized by adult-onset retinitis pigmentosa, anosmia, sensory neuropathy and phytanic acidaemia. Many cases are caused by mutations in peroxisomal oxygenase phytanoyl-CoA 2-hydroxylase (PAHX) which catalyses the initial alpha-oxidation step in the degradation of phytanic acid. Both pro and mature forms of recombinant PAHX were produced in Escherichia coli, highly purified, and shown to have a requirement for iron(II) as a co-factor and 2-oxoglutarate as a co-substrate. Sequence analysis in the light of crystallographic data for other members of the 2-oxoglutarate-dependent oxygenase super-family led to secondary structural predictions for PAHX, which were tested by site-directed mutagenesis. The H175A and D177A mutants did not catalyse hydroxylation of phytanoyl-CoA, consistent with their assigned role as iron(II) binding ligands. The clinically observed P29S, Q176K, G204S, N269H, R275Q and R275W mutants were assayed for both 2-oxoglutarate and phytanoyl-CoA oxidation. The P29S mutant was fully active, implying that the mutation resulted in defective targeting of the protein to peroxisomes. Mutation of Arg-275 resulted in impaired 2-oxoglutarate binding. The Q176K, G204S and N269H mutations caused partial uncoupling of 2-oxoglutarate conversion from phytanoyl-CoA oxidation. The results demonstrate that the diagnosis of Refsum's disease should not solely rely upon PAHX assays for 2-oxoglutarate or phytanoyl-CoA oxidation. |
spellingShingle | Mukherji, M Chien, W Kershaw, N Clifton, I Schofield, C Wierzbicki, A Lloyd, MD Structure-function analysis of phytanoyl-CoA 2-hydroxylase mutations causing Refsum's disease. |
title | Structure-function analysis of phytanoyl-CoA 2-hydroxylase mutations causing Refsum's disease. |
title_full | Structure-function analysis of phytanoyl-CoA 2-hydroxylase mutations causing Refsum's disease. |
title_fullStr | Structure-function analysis of phytanoyl-CoA 2-hydroxylase mutations causing Refsum's disease. |
title_full_unstemmed | Structure-function analysis of phytanoyl-CoA 2-hydroxylase mutations causing Refsum's disease. |
title_short | Structure-function analysis of phytanoyl-CoA 2-hydroxylase mutations causing Refsum's disease. |
title_sort | structure function analysis of phytanoyl coa 2 hydroxylase mutations causing refsum s disease |
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