Mechanistic insights into the dimethylsulfoniopropionate synthesis enzyme BurB.

Unlabelled: Dimethylsulfoniopropionate (DMSP) is one of the most abundant organosulfur molecules on Earth. It possesses various physiological functions in microorganisms and plays key roles in the global climate regulation. BurB, a SET (Suppressor of variegation, Enhancer of zeste and Trithorax) domain-containing enzyme identified from , initiates DMSP synthesis by methylating methionine (Met) to -methyl-methionine (SMM), with -adenosyl methionine (SAM) as a methyl donor.

Mechanistic Insight into the Cleavage Site Specificity of Collagenase VhaC to the Y-G Bonds in Collagen.

M9 collagenases have various biotechnological and medical applications due to their high activity and specificity to collagen. Although the collagenolytic mechanism of M9 collagenases has been studied, the molecular basis for their cleavage site specificity remains unknown. Here, the mechanism of the Y-G bond cleavage site specificity of M9 collagenase VhaC was studied.

Structural and molecular basis for phosphate recognition by SAR11 bacteria.

Phosphorus is a critical limiting nutrient that constrains the survival, growth, and reproduction of marine microorganisms in nutrient-limited ecosystems. Phosphorus exists in the environment in both organic and inorganic forms, with phosphate being the predominant form of inorganic phosphorus. SAR11 bacteria, a group of oligotrophic marine bacteria, possess high-affinity transporters for limiting nutrients such as phosphate, nitrogen, and organic carbon, enabling them to dominate in nutrient-depleted environments.

Novel regulatory mechanism of choline-O-sulfate and choline catabolism by two BetIs in Alphaproteobacteria.

Choline-O-sulfate (COS) and choline are ubiquitous in the environment, and diverse bacteria catabolize them into glycine betaine for osmoprotection or as a carbon and/or nitrogen source. The characterized genes involved in COS and choline catabolism are usually clustered in the genome with one regulatory gene, . Here, we report a novel regulatory mechanism of COS and choline catabolism by two BetIs in the model marine Roseobacter group bacterium DSS-3.

Inositol phosphates as an overlooked phosphorous source in marine ecosystems.

Inositol phosphates, common phosphorus storage compounds that are also crucial for eukaryotic cell signaling, constitute a significant portion of dissolved organic phosphorus in coastal waters. The hydrolysis of inositol phosphates could be an important contributor to phosphorus cycling in phosphorus-limited marine ecosystems, yet this process remains poorly understood in marine contexts. In this study, we reveal substantial concentrations of inositol phosphates in marine macrophytes, including green, brown, and red algae as well as common seagrasses, suggesting that these organisms are likely major biological sources of inositol phosphates in the oceans.

Multiple Hall Effects in Antiferromagnetic-Ferroelectric Heterostructures.

Distinct Hall effects are crucial for both theoretical study and practical applications in spintronics, valleytronics, and layertronics, but effectively controlling these effects in 2D antiferromagnets remains challenging. Here, a novel mechanism for achieving controllable Hall effects is proposed in A-type bilayer antiferromagnets sandwiched between ferroelectric layers. Based on a tight-binding model analysis, we demonstrate that by selectively reversing the polarization orientation of top or bottom ferroelectric layer, the bilayer antiferromagnets exhibit transitions between layer Hall, layer spin Hall, and valley layer spin Hall effects, driven by symmetry breaking or restoration as well as relative shift between antiferromagnetic and ferroelectric bands.

Potential of Marine Bacterial Metalloprotease A69 in the Preparation of Antarctic Krill Peptides with Multi-Bioactivities.

Antarctic krill () is a nutrient-rich marine resource. Although several terrestrial proteases have been used to prepare Antarctic krill peptides (AKPs), there has been no report on the preparation of AKPs using a marine protease. Here, marine bacterial protease A69 was used to prepare AKPs with multi-bioactivities.

Central adiposity indices and inflammatory markers mediate the association between life's crucial 9 and periodontitis in US adults.

Background: Periodontitis, a chronic inflammatory disease, is closely linked to cardiovascular health. While Life's Essential 8 (LE8) evaluates cardiovascular metrics, recent recommendations suggest incorporating psychological health (PHQ-9) to form Life's Crucial 9 (LC9). However, evidence regarding the utility of LC9 in periodontal disease remains limited.

Complete xylan utilization pathway and regulation mechanisms involved in marine algae degradation by cosmopolitan marine and human gut microbiota.

β-1,3-xylan, typically found in marine algae as a major cell wall polysaccharide, represents an overlooked pool of organic carbon in global oceans. Whilst our understanding of microbial catabolism of xylans has improved significantly, particularly from biotransformations of terrestrial plant biomass that are typically composed of β-1,4-xylans, knowledge on how microbes utilize β-1,3-xylan remains limited. Here, we describe the discovery of a complete pathway for β-1,3-xylan catabolism and its regulation in a marine bacterium, Vibrio sp.

Crystal structure and catalytic mechanism of PL35 family glycosaminoglycan lyases with an ultrabroad substrate spectrum.

Recently, a new class of glycosaminoglycan (GAG) lyases (GAGases) belonging to PL35 family has been discovered with an ultrabroad substrate spectrum that can degrade three types of uronic acid-containing GAGs (hyaluronic acid, chondroitin sulfate and heparan sulfate) or even alginate. In this study, the structures of GAGase II from and GAGase VII from DSM 17393 were determined at 1.9 and 2.

Characterization of the Structure and Function of the Photosynthetic RC-LH1 Core Supercomplex From Rhodospirillum rubrum.

Photosynthetic reaction center-light harvesting 1 (RC-LH1) core supercomplexes are essential for energy capture and electron transport in purple bacteria. Rhodospirillum rubrum, a model organism for bacterial photosynthesis, features an RC-LH1 architecture with a closed LH1 ring and lacks the peripheral LH2 antenna in the photosynthetic membranes. How this unique RC-LH1 supercomplex performs energy transfer and quinone transport remains unclear.

Crp and Arc system directly regulate the transcription of NADH dehydrogenase genes in nitrate and nitrite respiration.

NADH oxidation by NADH dehydrogenases (NDHs) is crucial for feeding respiratory quinone pool and maintaining the balance of NADH/NAD. In the respiratory model organism , which possesses four NDHs, the longstanding notion had been that NDHs were not required under anoxic conditions until recent studies demonstrated their role in extracellular electron transfer. However, the role of each NDH, particularly under anoxic conditions, has not been characterized.

Symmetry-adjusted cryo-EM analysis unveils the detailed linker protein CsoS2 interactions within the α-carboxysome shell.

Excessive symmetry in cryo-EM data processing can distort key structural details of bacterial microcompartments, highlighting the importance of balanced symmetry for accurate structural insights.

Cold-Adapted Lipid A from Polaribacter sp. SM1127: A Study of Structural Heterogeneity and Immunostimulatory Properties.

Polaribacter sp. SM1127, a cold-adapted marine Gram-negative bacterium isolated from Laminaria in Arctic waters, plays a crucial role in nutrient cycling and biopolymer degradation in cold environments. Additionally, its exopolysaccharide (EPS) exhibits promising biotechnological potential, including antioxidant and wound-healing properties.

Carbohydrate deacetylase, a key enzyme in oxidative chitin degradation, is evolutionarily linked to amino acid deacetylase.

The microbial oxidative cleavage of chitin, the second most abundant biopolymer in nature, generates a substantial amount of oxidized amino sugar, 2-(acetylamino)-2-deoxy-D-gluconic acid (GlcNAc1A). The catabolism of GlcNAc1A is key to the oxidative chitin degradation pathway. However, the molecular mechanism and evolution underlying this pathway remain elusive.

sp. nov., a DNA-hydrolysing bacterium isolated from intertidal sediment.

A Gram-stain-negative, yellow-pigmented, non-flagellated, motile by gliding, aerobic and rod-shaped bacterial strain, designated SM2212, was isolated from intertidal sediment of Aoshan Bay in Qingdao, China. The strain grew at 5-35 °C and with 0.5-5.

-4-hydroxy-L-proline catabolism by in the ocean.

Unlabelled: Free -4-hydroxy-L-proline (T4LHyp), a non-proteinogenic amino acid, is mainly released from the degradation of collagen, hydroxyproline-rich glycoproteins, and some peptide antibiotics in nature. Although it has been known that some terrestrial bacteria utilize T4LHyp as carbon and nitrogen source via a T4LHyp gene cluster, which and how marine microorganisms catabolize T4LHyp still remains unclear. Here, five T4LHyp-utilizing marine bacterial strains, sp.

Genomic analysis of Vibrio sp. D3 reveals its role in marine sulfur cycling.

Dimethylsulfoniopropionate (DMSP) is an important organosulfur compound, with key roles in global carbon and sulfur cycling, stress tolerance, chemotaxis, and, potentially, climate regulation. The strain Vibrio sp. D3 was isolated from the surface seawater samples in Qingdao coastal area, which could grow on DMSP as sole carbon source.

Annealing synchronizes the TOM complex with Tom7 in a new orientation.

Annealing is an ideal approach to synchronizing soluble proteins into their minimum-energy states via tandem heating and cooling treatments. Like soluble proteins, many membrane proteins also suffer intrinsic structural flexibility, the major obstacle to high-resolution structural determination. How to apply annealing onto membrane proteins remains unexplored.

Alginate catabolic systems in marine bacteria.

Brown algae, constituting the second largest group of marine macroalgae, fix significant amounts of inorganic carbon into alginate, the most abundant polysaccharide found in their cell walls. Alginate serves as an important macromolecular carbon source for marine bacteria. The catabolism of alginate by bacteria is an important step in the marine carbon cycle, and this area of research has attracted growing interests over the past decade.

Direct Preparation of Alginate Oligosaccharides from Brown Algae by an Algae-Decomposing Alginate Lyase AlyP18 from the Marine Bacterium A3.

Alginate oligosaccharides (AOs), derived from alginate degradation, exhibit diverse biological activities and hold significant promise in various fields. The enzymatic preparation of AOs relies on alginate lyases, which offers distinct advantages. In contrast to the conventional use of sodium alginate derived from brown algae as the substrate for the enzymatic preparation of AOs, AO preparation directly from brown algae is more appealing due to its time and energy efficiency.

Genomic analysis of Rhodopirellula sp. P2 reveals its role in fucoidan degradation.

Fucoidan, the main polysaccharide in various species of brown seaweed, has a high annual production. It is an important source of marine organic carbon and exhibits diverse biological activities and significant application potential. Rhodopirellula sp.