Bacterial microcompartments (MCPs) are widespread protein-based organelles that play important roles in the global carbon cycle and in the physiology of diverse bacteria, including a number of pathogens. MCPs consist of metabolic enzymes encapsulated within a protein shell. The main roles of MCPs are to concentrate enzymes together with their substrates (to increase reaction rates) and to sequester harmful metabolic intermediates.
View Article and Find Full Text PDFActa Crystallogr F Struct Biol Commun
May 2023
Methanobactins (MBs) are ribosomally produced and post-translationally modified peptides (RiPPs) that are used by methanotrophs for copper acquisition. The signature post-translational modification of MBs is the formation of two heterocyclic groups, either an oxazolone, pyrazinedione or imidazolone group, with an associated thioamide from an X-Cys dipeptide. The precursor peptide (MbnA) for MB formation is found in a gene cluster of MB-associated genes.
View Article and Find Full Text PDFMethanobactins (MBs) are ribosomally synthesized and posttranslationally modified peptides (RiPPs) produced by methanotrophs for copper uptake. The posttranslational modification that defines MBs is the formation of two heterocyclic groups with associated thioamines from X-Cys dipeptide sequences. Both heterocyclic groups in the MB from Methylosinus trichosporium OB3b (MB-OB3b) are oxazolone groups.
View Article and Find Full Text PDFCurr Opin Microbiol
August 2021
Bacterial microcompartments are widespread organelles that play important roles in the environment and are associated with a number of human diseases. A key feature of bacterial MCPs is a selectively permeable protein shell that mediates the movement of substrates, products and cofactors in and out. Here we discuss current knowledge of selective transport across the protein shells of bacterial MCPs, including mechanisms, regulation and unanswered questions.
View Article and Find Full Text PDFMethanobactins (MBs) are small (<1,300-Da) posttranslationally modified copper-binding peptides and represent the extracellular component of a copper acquisition system in some methanotrophs. Interestingly, MBs can bind a range of metal ions, with some being reduced after binding, e.g.
View Article and Find Full Text PDFBacterial microcompartments are organelle-like structures composed entirely of proteins. They have evolved to carry out several distinct and specialized metabolic functions in a wide variety of bacteria. Their outer shell is constructed from thousands of tessellating protein subunits, encapsulating enzymes that carry out the internal metabolic reactions.
View Article and Find Full Text PDFBacterial microcompartments (MCPs) are extremely large (100-400 nm) and diverse proteinaceous organelles that compartmentalize multistep metabolic pathways, increasing their efficiency and sequestering toxic and/or volatile intermediates. This review highlights recent studies that have expanded our understanding of the diversity, structure, function, and potential biotechnological uses of MCPs. Several new types of MCPs have been identified and characterized revealing new functions and potential new associations with human disease.
View Article and Find Full Text PDFSeveral genes of the , , and operons are responsible for the metabolism of ethanolamine (EA) and 1,2-propanediol (PD) and are essential during the pathogenic lifecycles of various enteric pathogens. Studies concerning EA and PD metabolism have primarily focused on bacterial genera from the family , especially the genus . is a member of the phylum and is the causative agent of the rare but highly fatal foodborne disease listeriosis.
View Article and Find Full Text PDFBacterial microcompartments (MCPs) are proteinaceous organelles consisting of a metabolic pathway encapsulated within a selectively permeable protein shell. Hundreds of species of bacteria produce MCPs of at least nine different types, and MCP metabolism is associated with enteric pathogenesis, cancer, and heart disease. This review focuses chiefly on the four types of catabolic MCPs (metabolosomes) found in and : the propanediol utilization (), ethanolamine utilization (), choline utilization (), and glycyl radical propanediol () MCPs.
View Article and Find Full Text PDFBacterial microcompartments are protein-based organelles that carry out specialized metabolic functions in diverse bacteria. Their outer shells are built from several thousand protein subunits. Some of the architectural principles of bacterial microcompartments have been articulated, with lateral packing of flat hexameric BMC proteins providing the basic foundation for assembly.
View Article and Find Full Text PDFBacterial 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.
View Article and Find Full Text PDFMicrobiology (Reading)
December 2019
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.
View Article and Find Full Text PDFBacterial 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.
View Article and Find Full Text PDFBacterial microcompartments are giant protein-based organelles that encapsulate special metabolic pathways in diverse bacteria. Structural and genetic studies indicate that metabolic substrates enter these microcompartments by passing through the central pores in hexameric assemblies of shell proteins. Limiting the escape of toxic metabolic intermediates created inside the microcompartments would confer a selective advantage for the host organism.
View Article and Find Full Text PDFBacterial 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.
View Article and Find Full Text PDFThe diversity of non-canonical amino acids (ncAAs) endows proteins with new features for a variety of biological studies and biotechnological applications. The genetic code expansion strategy, which co-translationally incorporates ncAAs into specific sites of target proteins, has been applied in many organisms. However, there have been only few studies on pathogens using genetic code expansion.
View Article and Find Full Text PDFBacterial 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.
View Article and Find Full Text PDFProkaryotes use subcellular compartments for a variety of purposes. An intriguing example is a family of complex subcellular organelles known as bacterial microcompartments (MCPs). MCPs are widely distributed among bacteria and impact processes ranging from global carbon fixation to enteric pathogenesis.
View Article and Find Full Text PDFUnlabelled: In Salmonella enterica, 1,2-propanediol (1,2-PD) utilization (Pdu) is mediated by a bacterial microcompartment (MCP). The Pdu MCP consists of a multiprotein shell that encapsulates enzymes and cofactors for 1,2-PD catabolism, and its role is to sequester a reactive intermediate (propionaldehyde) to minimize cellular toxicity and DNA damage. For the Pdu MCP to function, the enzymes encapsulated within must be provided with a steady supply of substrates and cofactors.
View Article and Find Full Text PDFUnlabelled: Bacterial microcompartments (MCPs) are a diverse family of protein-based organelles composed of metabolic enzymes encapsulated within a protein shell. The function of bacterial MCPs is to optimize metabolic pathways by confining toxic and/or volatile metabolic intermediates. About 20% of bacteria produce MCPs, and there are at least seven different types.
View Article and Find Full Text PDFBacterial 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.
View Article and Find Full Text PDFBacterial microcompartments (MCPs) are protein-bound organelles that carry out diverse metabolic pathways in a wide range of bacteria. These supramolecular assemblies consist of a thin outer protein shell, reminiscent of a viral capsid, which encapsulates sequentially acting enzymes. The most complex MCP elucidated so far is the propanediol utilizing (Pdu) microcompartment.
View Article and Find Full Text PDFActa Crystallogr F Struct Biol Commun
December 2014
The EutL shell protein is a key component of the ethanolamine-utilization microcompartment, which serves to compartmentalize ethanolamine degradation in diverse bacteria. The apparent function of this shell protein is to facilitate the selective diffusion of large cofactor molecules between the cytoplasm and the lumen of the microcompartment. While EutL is implicated in molecular-transport phenomena, the details of its function, including the identity of its transport substrate, remain unknown.
View Article and Find Full Text PDFActa Crystallogr F Struct Biol Commun
November 2014
Prior studies have indicated that MJ1099 from Methanocaldococcus jannaschii has roles in the biosynthesis of tetrahydromethanopterin and methanofuran, two key cofactors of one-carbon (C1) metabolism in diverse organisms including the methanogenic archaea. Here, the structure of MJ1099 has been solved to 1.7 Å resolution using anomalous scattering methods.
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