Histidine 282 in 5-Aminolevulinate Synthase Affects Substrate Binding and Catalysis
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چکیده
منابع مشابه
Murine erythroid 5-aminolevulinate synthase: Adenosyl-binding site Lys221 modulates substrate binding and catalysis
5-Aminolevulinate synthase (ALAS) catalyzes the initial step of mammalian heme biosynthesis, the condensation between glycine and succinyl-CoA to produce CoA, CO2, and 5-aminolevulinate. The crystal structure of Rhodobacter capsulatus ALAS indicates that the adenosyl moiety of succinyl-CoA is positioned in a mainly hydrophobic pocket, where the ribose group forms a putative hydrogen bond with L...
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5-Aminolevulinate synthase of Rhodopseudomonas spheroides interacts with its cofactor, pyridoxal phosphate, and shows an absorption maximum at 430 nm with a probable shoulder at 320--330 nm. The enzyme-PLP complex absorbing at 430 nm is the predominant species at pH 7.2 and can be reduced by NaBH4 at neutral pH with a spectral shift of the absorption maximum to 325 nm. These data suggests the f...
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Biochemical characterization of polyketide synthases (PKSs) has relied on synthetic substrates functionalized as electrophilic esters to acylate the enzyme and initiate the catalytic cycle. In these efforts, N-acetylcysteamine thioesters have typically been employed for in vitro studies of full PKS modules as well as excised domains. However, substrate engineering approaches to control the cata...
متن کاملRegulation of 5-aminolevulinate synthase mRNA in different rat tissues.
cDNA clones for rat liver 5-aminolevulinate synthase have been isolated and used to examine mRNA levels in different rat tissues. Northern hybridization analysis of total RNA from various rat tissues showed the presence of a single 5-aminolevulinate synthase mRNA species of estimated length 2.3 kilobases. Primer extension and RNase mapping studies indicated that the mRNA is identical in all tis...
متن کاملHypoxic up-regulation of erythroid 5-aminolevulinate synthase.
The erythroid-specific isoform of 5-aminolevulinate synthase (ALAS2) catalyzes the rate-limiting step in heme biosynthesis. The hypoxia-inducible factor-1 (HIF-1) transcriptionally up-regulates erythropoietin, transferrin, and transferrin receptor, leading to increased erythropoiesis and hematopoietic iron supply. To test the hypothesis that ALAS2 expression might be regulated by a similar mech...
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ژورنال
عنوان ژورنال: Biochemistry
سال: 2007
ISSN: 0006-2960,1520-4995
DOI: 10.1021/bi062053k