Methionine γ-lyase (MGL) catalyzes the γ-elimination of l-methionine and its derivatives as well as the β-elimination of l-cysteine and its analogs. These reactions yield α-keto acids and thiols. The mechanism of chemical conversion of amino acids includes numerous reaction intermediates. The detailed analysis of MGL interaction with glycine, l-alanine, l-norvaline, and l-cycloserine was performed by pre-steady-state stopped-flow kinetics. The structure of side chains of the amino acids is important both for their binding with enzyme and for the stability of the external aldimine and ketimine intermediates. X-ray structure of the MGL·l-cycloserine complex has been solved at 1.6 Å resolution. The structure models the ketimine intermediate of physiological reaction. The results elucidate the mechanisms of the intermediate interconversion at the stages of external aldimine and ketimine formation.
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http://dx.doi.org/10.1074/jbc.M114.586511 | DOI Listing |
Front Genet
January 2025
Department of General Surgery, The Fourth Affiliated Hospital of Nanjing Medical University, Nanjing Medical University, Nanjing, Jiangsu, China.
Background: Neoadjuvant, endocrine, and targeted therapies have significantly improved the prognosis of breast cancer (BC). However, due to the high heterogeneity of cancer, some patients cannot benefit from existing treatments. Increasing evidence suggests that amino acids and their metabolites can alter the tumor malignant behavior through reshaping tumor microenvironment and regulation of immune cell function.
View Article and Find Full Text PDFJ Pineal Res
March 2025
College of Enology, Shaanxi Provincial Key Laboratory of Viti-Viniculture, Shaanxi Engineering Research Center of Characteristic Fruit Directional Design and Machining, Northwest A&F University, Yangling, China.
Melatonin is involved in biological adverse stress response and enhances the ability of yeast to adapt to adverse conditions. This study investigated the mechanism of exogenous melatonin addition to Saccharomyces cerevisiae (S. cerevisiae) under copper stress.
View Article and Find Full Text PDFFEBS J
January 2025
Department of Chemistry and Biochemistry, University of California, Santa Barbara, CA, USA.
1-Aminocyclopropane-1-carboxylate synthase (ACCS) catalyzes the conversion of S-adenosyl-methionine to 1-aminocyclopropane-1-carboxylate (ACC), a rate-limiting step in ethylene biosynthesis. A gene encoding a putative ACCS protein was identified in the human genome two decades ago. It has been shown to not exhibit any canonical ACC synthase activity and its true function remains obscure.
View Article and Find Full Text PDFThe effects of Acremonium terricola culture (ATC) on production performance, serum biochemical parameters, egg quality and amino acid contents in the yolk of eggs of Beijing You-chicken were conducted in the current study. A total of 216 Beijing You-chickens (330 days old) were randomly divided into 2 groups. The control group (CON) was fed a corn-soybean-based diet, and the experimental group was fed a basal diet supplemented with 0.
View Article and Find Full Text PDFPlant Physiol
December 2024
Department of Biology, University of Oxford, South Parks Road, Oxford OX1 3RB, UK.
The cysteine/arginine (Cys/Arg) branch of the N-degron pathway controls the stability of certain proteins with methionine (Met)-Cys N-termini, initiated by Met cleavage and Cys oxidation. In seeding plants, target proteins include the Group VII Ethylene Response Factors, which initiate adaptive responses to low oxygen (hypoxic) stress, as well as Vernalization 2 (VRN2) and Little Zipper 2 (ZPR2), which are involved in responses to endogenous developmental hypoxia. It is essential that these target proteins are only degraded by the N-degron pathway under the appropriate physiological conditions.
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