Nicotianamine (NA), a small molecule ubiquitous in plants, is an important divalent metal chelator and the main precursor of phytosiderophores. Nicotianamine synthase (NAS) is the enzyme catalyzing NA synthesis by the condensation of three aminopropyl moieties of S-adenosylmethionine (SAM) and the cyclization of one of them to form an azetidine ring. Here we report five crystal structures of an archaeal NAS from Methanothermobacter thermautotrophicus, either free or in complex with its product(s) and substrate(s). These structures reveal a two-domains fold arrangement of MtNAS, a small molecule related to NA (named here thermoNicotianamine or tNA), and an original mechanism of synthesis in a buried reaction chamber. This reaction chamber is open to the solvent through a small inlet, and a single active site allows the selective entrance of only one substrate at a time that is then processed and translocated stepwise.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2736904 | PMC |
http://dx.doi.org/10.1073/pnas.0904439106 | DOI Listing |
Spectrochim Acta A Mol Biomol Spectrosc
December 2024
School of Agriculture and Bioengineering, Heze University, Heze 274500, China. Electronic address:
Herin, the successful synthesis of a bis Schiff base (L) has been achieved using 2-hydroxy-1-naphthaldehyde and 1,3-diaminoguanidine as raw materials, which was further characterized by infrared spectroscopy, mass spectrometry, and nuclear magnetic resonance hydrogen spectrum. Moreover, spectroscopic experiments demonstrated that the probe L showed good selectivity and visual detectability for Al. Its detection limit (DL) is 2.
View Article and Find Full Text PDFBioresour Technol
December 2024
School of Energy Science and Engineering, Henan Polytechnic University, Jiaozuo 454000, China. Electronic address:
Biodegradable plastics (BPs) and lignite, both rich in organic matter, present significant challenges for efficient conversion into clean energy. This study examined the anaerobic co-digestion of BPs and lignite under controlled laboratory conditions. The results demonstrated that the co-digestion of polylactic acid (PLA) and lignite (at a 1:2 mass ratio, with 5 g PLA and 10 g lignite as the model system) rapidly acclimated to the anaerobic environment, enhancing cumulative biogas production by 57 % compared to the mono-digestion of lignite alone.
View Article and Find Full Text PDFColloids Surf B Biointerfaces
December 2024
School of Life Sciences, State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei University, Wuhan, Hubei 430042, China. Electronic address:
The CRISPR/Cas9 gene-editing technology, derived from the adaptive immune mechanisms of bacteria, has demonstrated remarkable advantages in fields such as gene function research and the treatment of genetic diseases due to its simplicity in design, precise targeting, and ease of use. Despite challenges such as off-target effects and cytotoxicity, effective spatiotemporal control strategies have been achieved for the CRISPR/Cas9 system through precise regulation of Cas9 protein activity as well as engineering of guide RNAs (gRNAs). This review provides a comprehensive analysis of the core components and functional mechanisms underlying the CRISPR/Cas9 system, highlights recent advancements in spatiotemporal control strategies, and discusses future directions for development.
View Article and Find Full Text PDFCell Chem Biol
December 2024
Department of Molecular Biology and Center for Computational and Integrative Biology, Massachusetts General Hospital, Boston, MA 02114, USA; Department of Genetics, Harvard Medical School, Boston, MA 02115, USA; Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA. Electronic address:
The surge of antimicrobial resistance threatens efficacy of current antibiotics, particularly against Pseudomonas aeruginosa, a highly resistant gram-negative pathogen. The asymmetric outer membrane (OM) of P. aeruginosa combined with its array of efflux pumps provide a barrier to xenobiotic accumulation, thus making antibiotic discovery challenging.
View Article and Find Full Text PDFLeuk Res
December 2024
Department of Hematopathy, Henan Institute of Hematology, The Affiliated Cancer Hospital of Zhengzhou University & Henan Cancer Hospital, Zhengzhou 450008, China; The Affiliated Cancer Hospital of Zhengzhou University & Henan Cancer Hospital, Zhengzhou 450008, China. Electronic address:
Background: APG-115 is a novel small-molecule selective inhibitor that destabilizes the p53-MDM2 complex and activates p53-mediated apoptosis in tumor cells. Anlotinib inhibits tumor angiogenesis and promotes apoptosis. In this study, we investigated the apoptotic effect and potential mechanism of APG-115 and anlotinib combination on AML cell lines with different p53 backgrounds.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!