5-aminolevulinate hydro-lyase (adding 5-aminolevulinate andcyclizing)
CYS 120;CYS 122;CYS 130(Zinc binding);GLU 232(Magnesium binding)
CYS 119;CYS 121;CYS 129(Zinc binding);GLU 231(Magnesium binding)
13C NMR as a probe for the study of enzyme-catalysed reactions: mechanism of action of 5-aminolevulinic acid dehydratase.
13C NMR studies of porphobilinogen synthase: observation of intermediates bound to a 280,000-dalton protein.
13C NMR studies of methylene and methine carbons of substrate bound to a 280,000-dalton protein, porphobilinogen synthase.
Small angle X-ray scattering study on bovine porphobilinogen synthase (5-aminolaevulinate dehydratase).
15N and 13C NMR studies of ligands bound to the 280,000-dalton protein porphobilinogen synthase elucidate the structures of enzyme-bound product and a Schiff base intermediate.
Probing of active site residues of the zinc enzyme 5-aminolevulinate dehydratase by spin and fluorescence labels.
5-Chlorolevulinate modification of porphobilinogen synthase identifies a potential role for the catalytic zinc.
Porphobilinogen synthase from Escherichia coli is a Zn(II) metalloenzyme stimulated by Mg(II).
CHARACTERIZATION, AND SEQUENCE OF 1-5; 95-134 AND 237-253.
Purification and characterization of 5-aminolaevulinic acid dehydratase from Escherichia coli and a study of the reactive thiols at the metal-binding domain.
Spatial proximity and sequence localization of the reactive sulfhydryls of porphobilinogen synthase.
5-Chloro[1,4-13C]levulinic acid modification of mammalian and bacterial porphobilinogen synthase suggests an active site containing two Zn(II).
Characterization of the role of the stimulatory magnesium of Escherichia coli porphobilinogen synthase.
Porphobilinogen synthase, the first source of heme's asymmetry.
The phylogenetically conserved histidines of Escherichia coli porphobilinogen synthase are not required for catalysis.
Purification, metal cofactor, N-terminal sequence and subunit composition of a 5-aminolevulinic acid dehydratase from the unicellular green alga Scenedesmus obliquus, mutant C-2A'.
Magnetic resonance studies on the active site and metal centers of Bradyrhizobium japonicum porphobilinogen synthase.
X-ray structure of 5-aminolaevulinate dehydratase, a hybrid aldolase.
Crystallization of 5-aminolaevulinic acid dehydratase from Escherichia coli and Saccharomyces cerevisiae and preliminary X-ray characterization of the crystals.
Mechanistic studies on E.coli 5-aminolaevulinic acid dehydratase.
X-ray structure of 5-aminolevulinic acid dehydratase from Escherichia coli complexed with the inhibitor levulinic acid at 2.0 A resolution.
Production, purification, and characterization of a Mg2+-responsive porphobilinogen synthase from Pseudomonas aeruginosa.
Pseudomonas aeruginosa contains a novel type V porphobilinogen synthase with no required catalytic metal ions.
High resolution crystal structure of a Mg2+-dependent porphobilinogen synthase.
The Schiff base complex of yeast 5-aminolaevulinic acid dehydratase with laevulinic acid.
MAD analyses of yeast 5-aminolaevulinate dehydratase: their use in structure determination and in defining the metal-binding sites.
Porphobilinogen synthase from pea: expression from an artificial gene, kinetic characterization, and novel implications for subunit interactions.
Inhibition of Escherichia coli porphobilinogen synthase using analogs of postulated intermediates.
Mechanistic basis for suicide inactivation of porphobilinogen synthase by 4,7-dioxosebacic acid, an inhibitor that shows dramatic species selectivity.
The X-ray structure of yeast 5-aminolaevulinic acid dehydratase complexed with two diacid inhibitors.
Mechanistic implications of mutations to the active site lysine of porphobilinogen synthase.
The x-ray structure of yeast 5-aminolaevulinic acid dehydratase complexed with substrate and three inhibitors.
Selenoxides inhibit delta-aminolevulinic acid dehydratase.
5-Aminolaevulinic acid dehydratase: metals, mutants and mechanism.
Species-specific inhibition of porphobilinogen synthase by 4-oxosebacic acid.
Structure of porphobilinogen synthase from Pseudomonas aeruginosa in complex with 5-fluorolevulinic acid suggests a double Schiff base mechanism.
X-RAY CRYSTALLOGRAPHY (1.66 ANGSTROMS) OF MUTANT D139N.
X-ray structure of a putative reaction intermediate of 5-aminolaevulinic acid dehydratase.
Control of tetrapyrrole biosynthesis by alternate quaternary forms of porphobilinogen synthase.
The X-ray structure of the plant like 5-aminolaevulinic acid dehydratase from Chlorobium vibrioforme complexed with the inhibitor laevulinic acid at 2.6 A resolution.
Tracking the evolution of porphobilinogen synthase metal dependence in vitro.
Structure of yeast 5-aminolaevulinic acid dehydratase complexed with the inhibitor 5-hydroxylaevulinic acid.
Structure of Chlorobium vibrioforme 5-aminolaevulinic acid dehydratase complexed with a diacid inhibitor.
Probing the active site of Pseudomonas aeruginosa porphobilinogen synthase using newly developed inhibitors.
(A) Exchange of double-bonded atoms; Schiff-base formation between Lys246 and P-side ALA substrate (see [17], [27] and [31]): (A1) Lys194 acts as a modulator to lower the pKa of the nucleophile Lys246. There are several subfamilies of the homologous enzymes, such as zinc-dependent (S00239, S00538 in EzCatDB), and zinc-independent (S00537, S00539) subfamilies. This enzyme belongs to zinc-dependent subfamily. According to the literature [36], the reaction proceeds as follows: (A) Exchange of double-bonded atoms; Schiff-base formation between Lys246 and P-side ALA substrate: (B) Exchange of double-bonded atoms; Schiff-base formation between Lys194 and A-side ALA substrate: (C) Isomerization; Shift of double-bond from N=C-C to N-C=C, forming an enamine intermediate at A-side: (D) Addition (C-C bond formation): (E) Addition (C-N bond formation): (F) Eliminative double-bond formation (releasing Lys194 at A-side): (G) Eliminative double-bond formation (releasing Lys246 at P-side): (H) Isomerization; Shift of double-bonds from N=C-C=C-C to N-C=C-C=C: However, although the first two reactions (A-B) and the last reaction (H) seem to be common to all the homologous enzymes (S00537, S00538, S00539 in EzCatDB), the rest of the reactions (D-G) have not been elucidated yet. The detailed mechanism must be as follows: (A2) Lys246 makes a nucleophilic attack on the carbonyl carbon of the substrate, ALA, at P-side, leading to formation of a tetrahedral carbinolamine transition-state. The carbinolamine oxygen of the transition-state is stabilized by the positive charge of Lys194. (A3) Lys194 acts as a general acid to protonate the carbinolamine oxygen of the transition-state, leading to formation of hydroxyl group, and then acts as a general base to deprotonate the sidechain of Lys246. (A4) The lone pair of the amine nitrogen of Lys246 makes a nucleophilic attack on the carbon atom of the carbinolamine transition-state, forming a Schiff-base. At the same time, Lys194 acts as a general acid to protonate the hydroxyl group of the carbinolamine, to facilitate the elimination of water molecule. (B) Exchange of double-bonded atoms; Schiff-base formation between Lys194 and A-side ALA substrate: (B1) Unprotonated sidechain of Lys194 acts as a nucleophile to attack on the carbonyl carbon of the substrate, ALA, at A-side, leading to formation of a carbinolamine transition-state. The carbinolamine oxygen of the transition-state is stabilized by the positive charge of the amino group of the ALA substrate at A-side. (B2) The amino group of the ALA substrate at A-side might act as a general acid to protonate the carbinolamine oxygen of the transition-state, leading to formation of hydroxyl group, and then act as a general base to deprotonate the sidechain of Lys194. (B3) The lone pair of the amine nitrogen of Lys194 makes a nucleophilic attack on the carbon atom of the carbinolamine transition-state, forming a Schiff-base. At the same time, the amino group of the ALA acts as a general acid to protonate the hydroxyl group of the carbinolamine, to facilitate the elimination of water molecule. (C) Isomerization; Shift of double-bond from N=C-C to N-C=C, forming an enamine intermediate at A-side: (C1) Hydroxide bound to zinc ion acts as a strong base to deprotonate C3 methylene of the Schiff-base intermediate at A-side, leading to formation of an enamine intermediate. (E) Addition (C-N bond formation): (E1) The unprotonated amino group of the ALA at A-side acts as a general base to deprotonate the amino group of the ALA at P-side. (E2) The amino group of the ALA at P-side makes a nucleophilic attack on the Schiff base of A-side, forming a cyclic intermediate. (E3) The protonated amino group of the ALA at A-side acts as a general acid to protonate the sidechain amine group of Lys194 at A-side. (F) Eliminative double-bond formation (releasing Lys194 at A-side): (F1) Lys246, which is covalently bound to the cyclic intermediate, acts as a general base to deprotonate the C2 atom of the intermediate (or originally C3 atom of ALA at A-side), and then acts as a general acid to protonate the eliminated group, Lys210. (F2) At the same time, Lys210 is eliminated from the intermediate; E2-like reaction. (G) Eliminative double-bond formation (releasing Lys246 at P-side): (G1) Lys210 acts as a general acid to protonate the eliminated group, the amino group of Lys246. (G2) The lone pair of enamine of the intermediate push the electron to form a new double bond, facilitating the elimination of Lys246; E1-like reaction. (H) Isomerization; Shift of double-bonds from N=C-C=C-C to N-C=C-C=C: (H1) Electrophilic Schiff-base assisted reaction. Lys246 acts as a general base to the C4 methylene of the intermediate (or originally C5 atom of ALA at P-side), leading to the shift of double-bonds.