Cloning, expression, and characterization of 5-aminolevulinic acid synthase from Rhodopseudomonas palustris KUGB306.
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Choi HP, Hong JW, Rhee KH, Sung HC
Cloning, expression, and characterization of 5-aminolevulinic acid synthase from Rhodopseudomonas palustris KUGB306.
FEMS Microbiol Lett. 2004 Jul 15;236(2):175-81.
- PubMed ID
- 15251194 [ View in PubMed]
- Abstract
The hemA gene encoding 5-aminolevulinic acid synthase (ALAS) was cloned from the genomic DNA of photosynthetic bacterium Rhodopseudomonas palustris KUGB306. The deduced protein (ALAS) of this gene contained 409 amino acids. The hemA gene was subcloned into an expression vector pGEX-KG and the encoded protein was overexpressed as a fusion protein with glutathione-S-transferase (GST) in Escherichia coli BL21. The recombinant ALAS was purified and isolated free of the fusion partner (GST) by affinity purification on glutathione-Sepharose 4B resin and cleavage of the purified fusion protein by thrombin protease. The optimum pH and temperature of the recombinant ALAS was found to be at pH 7.5-8.0 and 35-40 degrees C, respectively. The Km value of the enzyme was 2.01 mM for glycine and 49.55 microM for succinyl-CoA. The enzyme activity was strongly inhibited by Pb2+, Fe2+, Co2+, Cu2+, and Zn2+ at 1 mM, but slightly affected by Mg2+ and K+. The recombinant ALAS required pyridoxal 5'-phosphate (PLP) as a cofactor for catalysis. Removal of this cofactor led to complete loss of the activity. Ultraviolet-visible spectroscopy with the ALAS suggested the presence of an aldimine linkage between the enzyme and PLP.
DrugBank Data that Cites this Article
- Drug Targets
Drug Target Kind Organism Pharmacological Action Actions Pyridoxal phosphate 5-aminolevulinate synthase, erythroid-specific, mitochondrial Protein Humans UnknownCofactorDetails