Insights into the divergence of the photosynthetic LH1 complex obtained from structural analysis of the unusual photocomplexes of Roseospirillum parvum.

Purple phototrophic bacteria produce two kinds of light-harvesting complexes that function to capture and transmit solar energy: the core antenna (LH1) and the peripheral antenna (LH2). The apoproteins of these antennas, encoded respectively by the genes pufBA and pucBA within and outside the photosynthetic gene cluster, respectively, exhibit conserved amino acid sequences and structural topologies suggesting they were derived from a shared ancestor. Here we present the structures of two photosynthetic complexes from Roseospirillum (Rss.

The electrochemical ion membrane system (EIMs) enhanced light reactions of photosynthesis with intermittent electrical stimulation.

Despite the widespread application of electrochemical systems in bioproduction, their detailed effects on photosynthetic organisms remain to be explored. In this study, a three-chamber electrochemical ion membrane system (EIMs) was optimized for minimizing carbon resource interference in the cathode chamber, thereby elucidating the role of EIMs in the light reactions of photosynthesis. By applying intermittent electrical stimulation, the photosynthetic activity of microalgae was enhanced, manifesting as the promoted accumulation of intracellular ATP and NADPH, while allowing the collection of hydrogen and oxygen as by-products.

LcASR enhances tolerance to abiotic stress in Leymus chinensis and Arabidopsis thaliana by improving photosynthetic performance.

As a crucial forage grass, Leymus chinensis plays significant roles in soil and water conservation owing to its robust stress resistance. However, the underlying molecular mechanisms of its stress tolerance remain unclear. In this study, a novel gene, designated as LcASR (Abiotic Stress Resistance in Leymus chinensis), imparting resilience to both high light and drought, was identified.

Architecture of the spinach plastid-encoded RNA polymerase.

The plastid-encoded RNA polymerase serves as the principal transcription machinery within chloroplasts, transcribing over 80% of all primary plastid transcripts. This polymerase consists of a prokaryotic-like core enzyme known as the plastid-encoded RNA polymerase core, and is supplemented by newly evolved associated proteins known as PAPs. However, the architecture of the plastid-encoded RNA polymerase and the possible functions of PAPs remain unknown.

Non-releasing poly (ionic liquid) based hydrogel accelerates diabetic wound healing.

Persistent bacterial colonization, abnormal inflammatory responses, and impaired angiogenesis pose significant challenges to effective wound repair, particularly in diabetic wounds. Employing exogenous bioactive substances in wound dressings is a recognized approach to dynamically respond to the wound microenvironment and accelerate the repair process. However, this strategy can lead to the development of drug resistance and induce further tissue damage.

Enhancement of astaxanthin accumulation via energy reassignment by removing the flagella of Haematococcus pluvialis.

Astaxanthin biosynthesis in Haematococcus pluvialis is driven by energy. However, the effect of the flagella-mediated energy-consuming movement process on astaxanthin accumulation has not been well studied. In this study, the profiles of astaxanthin and NADPH contents in combination with the photosynthetic parameters with or without flagella enabled by pH shock were characterized.

Unleashing the Power of Evolution in Xylanase Engineering: Investigating the Role of Distal Mutation Regulation.

The drive to enhance enzyme performance in industrial applications frequently clashes with the practical limitations of exhaustive experimental screening, underscoring the urgency for more refined and strategic methodologies in enzyme engineering. In this study, xylanase Xyl-1 was used as the model, coupling evolutionary insights with energy functions to obtain theoretical potential mutants, which were subsequently validated experimentally. We observed that mutations in the nonloop region primarily aimed at enhancing stability and also encountered selective pressure for activity.

Molecular structure and characterization of the Thermochromatium tepidum light-harvesting 1 photocomplex produced in a foreign host.

Purple phototrophic bacteria possess light-harvesting 1 and reaction center (LH1-RC) core complexes that play a key role in converting solar energy to chemical energy. High-resolution structures of LH1-RC and RC complexes have been intensively studied and have yielded critical insight into the architecture and interactions of their proteins, pigments, and cofactors. Nevertheless, a detailed picture of the structure and assembly of LH1-only complexes is lacking due to the intimate association between LH1 and the RC.

Therapeutic effect of ginkgetin on smoke-induced airway inflammation by down-regulating the c/EBPβ signaling pathway and CCL2 expression.

Ethnopharmacological Relevance: Ginkgo biloba leaf and seed have been traditionally used in ancient China for the treatment of cough and asthma. However, there is limited literature available on the anti-COPD effects and mechanisms of Ginkgo biloba.

Aims Of The Study: The aim of this study was to comprehensively investigate the therapeutic potential of ginkgo extracts in COPD through a combination of in vivo and in vitro functional experiments.

Energy Transfer and Exciton Relaxation in B880-B800-RC Complex through Two-Dimensional Electronic Spectroscopy.

The light-harvesting (LH) and reaction center (RC) core complex of purple bacterium , B880-B800-RC, are different from those of the typical photosynthetic unit, (B850-B800)-B880-RC. To investigate the excitation flowing dynamics in this unique complex, two-dimensional electronic spectroscopy is employed. The obtained time constants for the exciton relaxation in B880, exciton relaxation in B800, B800 → B880 energy transfer (EET), and B880 → closed RC EET are 43 fs, 177 fs, 1.

Light-Quality-Adapted Carotenoid Photoprotection in the Photosystem of .

The photosystem of filamentous anoxygenic phototroph (.) comprises a light-harvesting (LH) complex encircling a reaction center (RC), which intensely absorbs blue-green light by carotenoid (Car) and near-infrared light by bacteriochlorophyll (BChl). To explore the influence of light quality (color) on the photosynthetic activity, we compared the pigment compositions and triplet excitation dynamics of the LH-RCs from .

Microbial metabolism of diosgenin by a novel isolated Mycolicibacterium sp. HK-90: A promising biosynthetic platform to produce 19-carbon and 21-carbon steroids.

Green manufacture of steroid precursors from diosgenin by microbial replacing multistep chemical synthesis has been elusive. It is currently limited by the lack of strain and degradation mechanisms. Here, we demonstrated the feasibility of this process using a novel strain Mycolicibacterium sp.

High-resolution structure and biochemical properties of the LH1-RC photocomplex from the model purple sulfur bacterium, Allochromatium vinosum.

The mesophilic purple sulfur phototrophic bacterium Allochromatium (Alc.) vinosum (bacterial family Chromatiaceae) has been a favored model for studies of bacterial photosynthesis and sulfur metabolism, and its core light-harvesting (LH1) complex has been a focus of numerous studies of photosynthetic light reactions. However, despite intense efforts, no high-resolution structure and thorough biochemical analysis of the Alc.

Structures and organizations of PSI-AcpPCI supercomplexes from red tidal and coral symbiotic photosynthetic dinoflagellates.

Marine photosynthetic dinoflagellates are a group of successful phytoplankton that can form red tides in the ocean and also symbiosis with corals. These features are closely related to the photosynthetic properties of dinoflagellates. We report here three structures of photosystem I (PSI)-chlorophylls (Chls) /-peridinin protein complex (PSI-AcpPCI) from two species of dinoflagellates by single-particle cryoelectron microscopy.

Multi-point immobilization of GH 11 endo-β-1,4-xylanase on magnetic MOF composites for higher yield of xylo-oligosaccharides.

GH 11 endo-β-1,4-xylanase (Xy) was a crucial enzyme for xylooligosaccharides (XOS) production. The lower reusability and higher cost of purification has limited the industrial application of Xy. Addressing these challenges, our study utilized various immobilization techniques, different supports and forces for Xy immobilization.

Structural insights into photosystem II supercomplex and trimeric FCP antennae of a centric diatom Cyclotella meneghiniana.

Diatoms are dominant marine algae and contribute around a quarter of global primary productivity, the success of which is largely attributed to their photosynthetic capacity aided by specific fucoxanthin chlorophyll-binding proteins (FCPs) to enhance the blue-green light absorption under water. We purified a photosystem II (PSII)-FCPII supercomplex and a trimeric FCP from Cyclotella meneghiniana (Cm) and solved their structures by cryo-electron microscopy (cryo-EM). The structures reveal detailed organizations of monomeric, dimeric and trimeric FCP antennae, as well as distinct assemblies of Lhcx6_1 and dimeric FCPII-H in PSII core.

Carotenoid-Mediated Long-Range Energy Transfer in the Light Harvesting-Reaction Center Complex from Photosynthetic Bacterium .

The light harvesting-reaction center complex (LH-RC) of binds bacteriochlorophylls (BChls ), B800 and B880, absorbing around 800 and 880 nm, respectively. We comparatively investigated the interband excitation energy transfer (EET) dynamics of the wild-type LH-RC (wtLH-RC) of . and its carotenoid (Car)-less mutant (m-LH-RC) and found that Car can boost the B800 → B880 EET rate from (2.

Paddy cultivation in degraded karst wetland soil can significantly improve the physiological and ecological functions of carbon-fixing resident microorganisms.

Microorganisms play an important role in carbon fixation in karst wetland soils. However, the carbon fixation capacity of karst wetland soils and active microorganisms involved in the carbon fixation process are poorly understood. In this study, carbon fixation capacity and active microorganisms involved in the fixation of inorganic carbon into organic carbon were studied in native, naturally degraded, and reclaimed karst wetland soils by the combination of stable isotope probing (SIP) and high-throughput sequencing.

Mechanistic Insights into the Halophilic Xylosidase Xylo-1 and Its Role in Xylose Production.

The Xylo-1 xylosidase, which belongs to the GH43 family, exhibits a high salt tolerance. The present study demonstrated that the catalytic activity of Xylo-1 increased by 195% in the presence of 5 M NaCl. Additionally, the half-life of Xylo-1 increased 25.

Propeptide-Mediated Allosteric Regulation of Xylanase Xyl-1: An Integrated Experimental and Computational Analysis.

Most GH11 family endo-β-1,4-xylanases contain a propeptide region linked to the N-terminal region. The mechanistic basis of this region harboring key regulation information for enzyme function, however, remains poorly understood. We reported an investigation on the allosteric regulation mechanism of the propeptide based on biochemical characterization, molecular dynamics simulations, and evolutionary analysis.

miR5298b regulated taxol biosynthesis by acting on TcNPR3, resulting in an alleviation of the strong inhibition of the TcNPR3-TcTGA6 complex in Taxus chinensis.

Taxol, a valuable but rare secondary metabolite of the genus Taxus, is an effective anticancer drug. Understanding the regulation of taxol biosynthesis may provide a means to increase taxol content. The microRNA miR5298b was found to promote the accumulation of taxol and upregulate several taxol biosynthesis genes, including DBAT, TASY, and T5H, as demonstrated by experiments using the overexpression and mimicry of transient leaves.