Sericin-based nanotherapeutics: A dual-action biological macromolecule for anti-urolithiatic and antibacterial applications.

Kidney stone (urolithiasis) is a prevalent global health issue with limited safe and cost-effective treatment options. This study investigates the anti-urolithiasis potential of sericin, a silk protein sustainably extracted from Bombyx mori cocoons, and its innovative nanoparticle formulations. Biocompatible sericin, sericin nanoparticles, and sericin coupled with a phytate chelator were developed and meticulously characterized.

A Systemic Review on Fitness and Survival of in Dynamic Environment and Conceivable Ways of Its Mitigation.

Gastroenteritis caused by non-typhoidal still prevails resulting in several recent outbreaks affecting many people worldwide. The presence of invasive non-typhoidal is exemplified by several characteristic symptoms and their severity relies on prominent risk factors. The persistence of this pathogen can be attributed to its broad host range, complex pathogenicity and virulence and adeptness in survival under challenging conditions inside the host.

Microbial production of N-acetyl-D-glucosamine (GlcNAc) for versatile applications: Biotechnological strategies for green process development.

N-acetyl-d-glucosamine (GlcNAc) is a commercially important amino sugar for its wide range of applications in pharmaceutical, food, cosmetics and biofuel industries. In nature, GlcNAc is polymerised into chitin biopolymer, which is one of the major constituents of fungal cell wall and outer shells of crustaceans. Sea food processing industries generate a large volume of chitin as biopolymeric waste.

Potential utility of bacterial protein nanoreactor for sustainable in-situ biocatalysis in wide range of bioprocess conditions.

Bacterial microcompartments (MCPs) are proteinaceous organelles that natively encapsulates the enzymes, substrates, and cofactors within a protein shell. They optimize the reaction rates by enriching the substrate in the vicinity of enzymes to increase the yields of the product and mitigate the outward diffusion of the toxic or volatile intermediates. The shell protein subunits of MCP shell are selectively permeable and have specialized pores for the selective inward diffusion of substrates and products release.

Genetic Characterization of a Glycyl Radical Microcompartment Used for 1,2-Propanediol Fermentation by Uropathogenic Escherichia coli CFT073.

Bacterial microcompartments (MCPs) are widespread protein-based organelles composed of metabolic enzymes encapsulated within a protein shell. The function of MCPs is to optimize metabolic pathways by confining toxic and/or volatile pathway intermediates. A major class of MCPs known as glycyl radical MCPs has only been partially characterized.

Engineering the PduT shell protein to modify the permeability of the 1,2-propanediol microcompartment of .

Bacterial microcompartments (MCPs) are protein-based organelles that consist of metabolic enzymes encapsulated within a protein shell. The function of MCPs is to optimize metabolic pathways by increasing reaction rates and sequestering toxic pathway intermediates. A substantial amount of effort has been directed toward engineering synthetic MCPs as intracellular nanoreactors for the improved production of renewable chemicals.

A Bacterial Microcompartment Is Used for Choline Fermentation by Escherichia coli 536.

Bacterial choline degradation in the human gut has been associated with cancer and heart disease. In addition, recent studies found that a bacterial microcompartment is involved in choline utilization by and species. However, many aspects of this process have not been fully defined.

The N Terminus of the PduB Protein Binds the Protein Shell of the Pdu Microcompartment to Its Enzymatic Core.

Bacterial microcompartments (MCPs) are extremely large proteinaceous organelles that consist of an enzymatic core encapsulated within a complex protein shell. A key question in MCP biology is the nature of the interactions that guide the assembly of thousands of protein subunits into a well-ordered metabolic compartment. In this report, we show that the N-terminal 37 amino acids of the PduB protein have a critical role in binding the shell of the 1,2-propanediol utilization (Pdu) microcompartment to its enzymatic core.

The function of the PduJ microcompartment shell protein is determined by the genomic position of its encoding gene.

Bacterial microcompartments (MCPs) are complex organelles that consist of metabolic enzymes encapsulated within a protein shell. In this study, we investigate the function of the PduJ MCP shell protein. PduJ is 80% identical in amino acid sequence to PduA and both are major shell proteins of the 1,2-propanediol (1,2-PD) utilization (Pdu) MCP of Salmonella.

A putative low-molecular-mass penicillin-binding protein (PBP) of Mycobacterium smegmatis exhibits prominent physiological characteristics of DD-carboxypeptidase and beta-lactamase.

DD-carboxypeptidases (DD-CPases) are low-molecular-mass (LMM) penicillin-binding proteins (PBPs) that are mainly involved in peptidoglycan remodelling, but little is known about the dd-CPases of mycobacteria. In this study, a putative DD-CPase of Mycobacterium smegmatis, MSMEG_2433 is characterized. The gene for the membrane-bound form of MSMEG_2433 was cloned and expressed in Escherichia coli in its active form, as revealed by its ability to bind to the Bocillin-FL (fluorescent penicillin).

Selective molecular transport through the protein shell of a bacterial microcompartment organelle.

Bacterial microcompartments are widespread prokaryotic organelles that have important and diverse roles ranging from carbon fixation to enteric pathogenesis. Current models for microcompartment function propose that their outer protein shell is selectively permeable to small molecules, but whether a protein shell can mediate selective permeability and how this occurs are unresolved questions. Here, biochemical and physiological studies of structure-guided mutants are used to show that the hexameric PduA shell protein of the 1,2-propanediol utilization (Pdu) microcompartment forms a selectively permeable pore tailored for the influx of 1,2-propanediol (the substrate of the Pdu microcompartment) while restricting the efflux of propionaldehyde, a toxic intermediate of 1,2-propanediol catabolism.

Diverse bacterial microcompartment organelles.

Bacterial microcompartments (MCPs) are sophisticated protein-based organelles used to optimize metabolic pathways. They consist of metabolic enzymes encapsulated within a protein shell, which creates an ideal environment for catalysis and facilitates the channeling of toxic/volatile intermediates to downstream enzymes. The metabolic processes that require MCPs are diverse and widely distributed and play important roles in global carbon fixation and bacterial pathogenesis.

Virulence factors are released in association with outer membrane vesicles of Pseudomonas syringae pv. tomato T1 during normal growth.

Outer membrane vesicles (OMVs) are released from Pseudomonas syringae pv. tomato T1 (Pst T1) during their normal growth. These extracellular compartments are comprised of a complete set of biological macromolecules that includes proteins, lipids, lipopolysaccharides, etc.

Moderate deacylation efficiency of DacD explains its ability to partially restore beta-lactam resistance in Escherichia coli PBP5 mutant.

Of the five dd-carboxypeptidases in Escherichia coli, only PBP5 demonstrates its physiological significance by maintaining cell shape and intrinsic beta-lactam resistance. DacD can partially compensate for the lost beta-lactam resistance in PBP5 mutant, although its biochemical reason is unclear. To understand the mechanism(s) underlying such behaviour, we constructed soluble DacD (sDacD) and compared its biophysical and biochemical properties with those of sPBP5, in vitro.

Differential expression of membrane proteins helps Antarctic Pseudomonas syringae to acclimatize upon temperature variations.

Antarctic bacteria are adapted to the extremely low temperature. The transcriptional and translational machineries of these bacteria are adapted to the sub-zero degrees of temperature. Studies directed towards identifying the changes in the protein profiles during changes in the growth temperatures of an Antarctic bacterium Pseudomonas syringae Lz4W may help in understanding the molecular basis of cold adaptation.

PBP5, PBP6 and DacD play different roles in intrinsic β-lactam resistance of Escherichia coli.

Escherichia coli PBP5, PBP6 and DacD, encoded by dacA, dacC and dacD, respectively, share substantial amino acid identity and together constitute ~50 % of the total penicillin-binding proteins of E. coli. PBP5 helps maintain intrinsic β-lactam resistance within the cell.

Differences in active-site microarchitecture explain the dissimilar behaviors of PBP5 and 6 in Escherichia coli.

Out of the four DD-carboxypeptidases (DD-CPases) in Escherichia coli, only penicillin-binding protein (PBP) 5 performs physiological functions such as maintaining cell shape; its nearest homolog, PBP6, cannot perform such functions. Moreover, unlike PBP6, PBP5 efficiently processes both beta-lactam, and peptide substrates. The crystal structure of PBP5 reveals strong inter-residue hydrogen-bonding interactions around the active site, which favor its catalytic activity.

Deletion of penicillin-binding protein 5 (PBP5) sensitises Escherichia coli cells to beta-lactam agents.

Escherichia coli penicillin-binding protein 5 (PBP5), a dd-carboxypeptidase encoded by the dacA gene, plays a key role in the maintenance of cell shape. Although PBP5 shares one of the highest copy numbers among the PBPs, it is not essential for cell survival. To determine the effect of this redundant PBP on beta-lactam antibiotic susceptibility, PBP5 was deleted from O-antigen-negative E.

A weak DD-carboxypeptidase activity explains the inability of PBP 6 to substitute for PBP 5 in maintaining normal cell shape in Escherichia coli.

Penicillin-binding protein (PBP) 5 plays a critical role in maintaining normal cellular morphology in mutants of Escherichia coli lacking multiple PBPs. The most closely related homologue, PBP 6, is 65% identical to PBP 5, but is unable to substitute for PBP 5 in returning these mutants to their wild-type shape. The relevant differences between PBPs 5 and 6 are localized in a 20-amino acid stretch of domain I in these proteins, which includes the canonical KTG motif at the active site.

Physiological functions of D-alanine carboxypeptidases in Escherichia coli.

Bacterial cell shape is, in part, mediated by the peptidoglycan (murein) sacculus. Penicillin-binding proteins (PBPs) catalyze the final stages of murein biogenesis and are the targets of beta-lactam antibiotics. Several low molecular mass PBPs including PBP4, PBP5, PBP6 and DacD seem to possess DD-carboxypeptidase (DD-CPase) activity, but these proteins are dispensable for survival in laboratory culture.