scholarly journals The X-ray structure of yeast 5-aminolaevulinic acid dehydratase (ALAD) complexed with substrate and inhibitors

2002 ◽  
Vol 58 (s1) ◽  
pp. c99-c99
Author(s):  
P. T. Erskine ◽  
L. Coates ◽  
S. P. Wood ◽  
P. M. Shoolingin-Jordan ◽  
R. Newbold ◽  
...  
Keyword(s):  
X Ray ◽  
Aminolaevulinic Acid ◽  
Acid Dehydratase ◽  
Aminolaevulinic Acid Dehydratase

scholarly journals Cloning, expression, purification, crystallization and preliminary crystallographic analysis of 5-aminolaevulinic acid dehydratase fromBacillus subtilis

2010 ◽  
Vol 66 (9) ◽  
pp. 1053-1055 ◽  
Author(s):  
Qianda Lu ◽  
Jinming Ma ◽  
Hui Rong ◽  
Jun Fan ◽  
Ye Yuan ◽  
...  
Keyword(s):  
Crystallographic Analysis ◽  
Diffusion Method ◽  
X Ray Diffraction ◽  
Gene Encoding ◽  
Data Set ◽  
X Ray ◽  
Aminolaevulinic Acid ◽  
Acid Dehydratase ◽  
Strain Bl21 ◽  
Aminolaevulinic Acid Dehydratase

5-Aminolaevulinic acid dehydratase (ALAD), a crucial enzyme in the biosynthesis of tetrapyrrole, catalyses the condensation of two 5-aminolaevulinic acid (ALA) molecules to form porphobilinogen (PBG). The gene encoding ALAD was amplified from genomic DNA ofBacillus subtilisand the protein was overexpressed inEscherichia colistrain BL21 (DE3). The protein was purified and crystallized with an additional MGSSHHHHHHSSGLVPRGSH– tag at the N-terminus of the target protein. Diffraction-quality single crystals were obtained by the hanging-drop vapour-diffusion method. An X-ray diffraction data set was collected at a resolution of 2.7 Å.

scholarly journals X-ray structure of a putative reaction intermediate of 5-aminolaevulinic acid dehydratase

2003 ◽  
Vol 373 (3) ◽  
pp. 733-738 ◽  
Author(s):  
Peter T. ERSKINE ◽  
Leighton COATES ◽  
Danica BUTLER ◽  
James H. YOUELL ◽  
Amanda A. BRINDLEY ◽  
...  
Keyword(s):  
Active Site ◽  
Catalytic Mechanism ◽  
Zinc Ion ◽  
Side Chain ◽  
Hydroxide Ion ◽  
X Ray ◽  
Aminolaevulinic Acid ◽  
Acid Dehydratase ◽  
Cyclic Intermediate ◽  
Aminolaevulinic Acid Dehydratase

The X-ray structure of yeast 5-aminolaevulinic acid dehydratase, in which the catalytic site of the enzyme is complexed with a putative cyclic intermediate composed of both substrate moieties, has been solved at 0.16 nm (1.6 Å) resolution. The cyclic intermediate is bound covalently to Lys263 with the amino group of the aminomethyl side chain ligated to the active-site zinc ion in a position normally occupied by a catalytic hydroxide ion. The cyclic intermediate is catalytically competent, as shown by its turnover in the presence of added substrate to form porphobilinogen. The findings, combined with those of previous studies, are consistent with a catalytic mechanism in which the C–C bond linking both substrates in the intermediate is formed before the C–N bond.

The X-ray structure of yeast 5-aminolaevulinic acid dehydratase complexed with substrate and three inhibitors 1 1Edited by R. Huber

2001 ◽  
Vol 312 (1) ◽  
pp. 133-141 ◽  
Author(s):  
P.T Erskine ◽  
R Newbold ◽  
A.A Brindley ◽  
S.P Wood ◽  
P.M Shoolingin-Jordan ◽  
...  
Keyword(s):  
X Ray ◽  
Aminolaevulinic Acid ◽  
Acid Dehydratase ◽  
Aminolaevulinic Acid Dehydratase

scholarly journals The X-ray structure of yeast 5-aminolaevulinic acid dehydratase complexed with two diacid inhibitors

FEBS Letters ◽  
2001 ◽  
Vol 503 (2-3) ◽  
pp. 196-200 ◽  
Author(s):  
P.T Erskine ◽  
L Coates ◽  
R Newbold ◽  
A.A Brindley ◽  
F Stauffer ◽  
...  
Keyword(s):  
X Ray ◽  
Aminolaevulinic Acid ◽  
Acid Dehydratase ◽  
Aminolaevulinic Acid Dehydratase

scholarly journals Characterization of the two 5-aminolaevulinic acid binding sites, the A- and P-sites, of 5-aminolaevulinic acid dehydratase from Escherichia coli

1995 ◽  
Vol 305 (1) ◽  
pp. 151-158 ◽  
Author(s):  
P Spencer ◽  
P M Jordan
Keyword(s):  
Schiff Base ◽  
Binding Sites ◽  
Metal Ion ◽  
Substrate Binding ◽  
Aminolaevulinic Acid ◽  
Acid Dehydratase ◽  
Carboxylate Groups ◽  
Catalytic Metal ◽  
A Site ◽  
Aminolaevulinic Acid Dehydratase

Experiments are described in which the individual properties of the two 5-aminolaevulinic acid (ALA) binding sites, the A-site and the P-site, of 5-aminolaevulinic acid dehydratase (ALAD) have been investigated. The ALA binding affinity at the A-site is greatly enhanced (at least 10-fold) on the binding of the catalytic metal ion (bound at the alpha-site). The nature of the catalytic metal ion, Mg2+ or Zn2+, also gave major variations in the substrate Km, P-site affinity for ALA, the effect of potassium and phosphate ions and the pH-dependence of substrate binding. Modification of the P-site by reaction of the enzyme-substrate Schiff base with NaBH4 and analysis of the reduced adduct by electro-spray mass spectrometry indicated a maximum of 1 mol of substrate incorporated/mol of subunit, correlating with a linear loss of enzyme activity. The reduced Schiff-base adduct was used to investigate substrate binding at the A-site by using rate-of-dialysis analysis. The affinity for ALA at the A-site of Mg alpha Zn beta ALAD was found to determine the Km for the reaction and was pH-dependent, with its affinity increasing from 1 mM at pH 6 to 70 microM at pH 8.5. The affinity of ALA at the P-site of Zn alpha An beta ALAD is proposed to limit the Km at pH values above 7, since the measured Kd for ALA at the A-site in 45 microM Tris, pH 8, was well below the observed Km (600 microM) under the same conditions. The amino group of the ALA molecule bound at the P-site was identified as a critical binding component for the A-site, explaining why ALA binding to ALAD is ordered, with the P-site ALA binding first. Structural requirements for ALA binding at the A- and P-sites have been identified: the P-site requires the carbonyl and carboxylate groups, whereas the A-site requires the amino, carbonyl and carboxylate groups of the substrate.

scholarly journals Investigation of the nature of the two metal-binding sites in 5-aminolaevulinic acid dehydratase from Escherichia coli

1994 ◽  
Vol 300 (2) ◽  
pp. 373-381 ◽  
Author(s):  
P Spencer ◽  
P M Jordan
Keyword(s):  
Escherichia Coli ◽  
Metal Ions ◽  
Metal Binding ◽  
Binding Sites ◽  
Metal Ion ◽  
Protein Fluorescence ◽  
Metal Binding Sites ◽  
Aminolaevulinic Acid ◽  
Acid Dehydratase ◽  
Aminolaevulinic Acid Dehydratase

Two distinct metal-binding sites, termed alpha and beta, have been characterized in 5-aminolaevulinic acid dehydratase from Escherichia coli. The alpha-site binds a Zn2+ ion that is essential for catalytic activity. This site can also utilize other metal ions able to function as a Lewis acid in the reaction mechanism, such as Mg2+ or Co2+. The beta-site is exclusively a transition-metal-ion-binding site thought to be involved in protein conformation, although a metal bound at this site only appears to be essential for activity if Mg2+ is to be bound at the alpha-site. The alpha- and beta-sites may be distinguished from one another by their different abilities to bind divalent-metal ions at different pH values. The occupancy of the beta-site with Zn2+ results in a decrease of protein fluorescence at pH 6. Occupancy of the alpha- and beta-sites with Co2+ results in u.v.-visible spectral changes. Spectroscopic studies with Co2+ have tentatively identified three cysteine residues at the beta-site and one at the alpha-site. Reaction with N-ethyl[14C]maleimide preferentially labels cysteine-130 at the alpha-site when Co2+ occupies the beta-site.

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