A chlorosome is a large and efficient light-harvesting antenna system found in some photosynthetic bacteria. This system comprises self-aggregates of bacteriochlorophyll (BChl) c, d, or e possessing a chiral 1-hydroxyethyl group at the 3-position, which plays a key role in the formation of the supramolecule. Biosynthesis of chlorosomal pigments involves stereoselective conversion of 3-vinyl group to 3-(1-hydroxyethyl) group facilitated by a 3-vinyl hydratase. This 3-vinyl hydration also occurs in BChl a biosynthesis, followed by oxidation that introduces an acetyl group at the 3-position. Herein, we present in vitro enzymatic assays of paralogous 3-vinyl hydratases derived from green sulfur bacteria, Chlorobaculum tepidum and Chlorobaculum limnaeum, the filamentous anoxygenic phototroph Chloroflexus aurantiacus, and the chloracidobacterium Chloracidobacterium thermophilum. All the hydratases showed hydration activities. The biosynthetic pathway of BChl a and other chlorosomal pigments is discussed considering the substrate specificity and stereoselectivity of the present hydratases.
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http://dx.doi.org/10.1007/s11120-017-0415-6 | DOI Listing |
FEMS Microbiol Lett
January 2025
Department of Bioscience and Biotechnology, Indian Institute of Technology Kharagpur, Kharagpur-721302, West Bengal, India.
Verona-integron-metallo-β-lactamase (VIM-2) is one of the most widespread class B β-lactamase responsible for β-lactam resistance. Although active-site residues help in metal binding, the residues nearing the active-site possess functional importance. Here, to decipher the role of such residues in the activity and stability of VIM-2, the residues E146, D182, N210, S207, and D213 were selected through in-silico analyses and substituted with alanine using site-directed mutagenesis.
View Article and Find Full Text PDFMicrobiome
January 2025
Instituto de Investigación de La Viña y El Vino, Escuela de Ingeniería Agraria, Universidad de León, Avenida de Portugal, 41, León, 24009, Spain.
Background: The main application of cork is the production of stoppers for wine bottles. Cork sometimes contains 2,4,6-trichloroanisole, a compound that, at a concentration of ng/L, produces an unpleasant musty odor that destroys the organoleptic properties of wine and results in enormous economic losses for wineries and cork industries. Cork can exhibit a defect known as yellow stain, which is associated with high levels of 2,4,6-trichloroanisole.
View Article and Find Full Text PDFChem Biodivers
January 2025
Birla Institute of Technology, Pharmaceutical Sciences & Technology, Dept of pharmaceutical sciences & Technology,BIT, Mesra, Ranchi, BIT,Mesra, Ranchi, 835215, Ranchi, INDIA.
This study was conducted to investigate the anti-obesity effects of bioactive fractions JAF2 and JAF3 from Justicia adhatoda (JA) in vitro using enzymatic assays, 3T3-L1 cells and in vivo using a monosodium glutamate-high-fat diet (MSG-HFD) model. High-Performance Thin Layer Chromatography coupled with Mass Spectrometry (HPTLC-MS-MSn) was finally utilized to analyze bioactive fractions for the compounds responsible for the activity. In vitro, the anti-obesity effects of JAF2 and JAF3 were assessed in 3T3-L1 adipocytes, revealing that JAF2 significantly reduced lipid and triglyceride levels.
View Article and Find Full Text PDFJ Exp Bot
January 2025
Department of Plant Ecophysiology, Faculty of Biology, Adam Mickiewicz University; Uniwersytetu Poznańskiego 6, 61-614 Poznań, Poland.
Through extensive research, nitroxyl (HNO) has emerged as a newly recognized redox signal in plant developmental and stress responses. The interplay between nitric oxide (●NO) and HNO entails a complex network of signaling molecules and regulatory elements sensitive to the environment's specific redox conditions. However, functional implications for HNO in cell signaling require more detailed studies, starting with identifying HNO-level switches.
View Article and Find Full Text PDFMicrosc Res Tech
January 2025
Programa de Pós-graduação Em Recursos Genéticos Vegetais, Universidade Federal Do Recôncavo da Bahia (UFRB), Programa de Pós-graduação Em Recursos Genéticos Vegetais, Cruz das Almas, Bahia, Brazil.
The genus Wittmackia has 44 species distributed in two centers of diversity: the Brazilian clade and the Caribbean clade. The Brazilian clade includes 29 species, with geographic distribution concentrated in the Northeast of Brazil. This study reports the morphology, ultrastructure, pollen viability and stigma receptivity by different microscopy techniques of 23 species of the genus Wittmackia endemic to Brazil and occurring in Atlantic Forest areas.
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