scholarly journals Control of Cell Wall Assembly by a Histone-Like Protein in Mycobacteria

2007 ◽  
Vol 189 (22) ◽  
pp. 8241-8249 ◽  
Author(s):  
Tomoya Katsube ◽  
Sohkichi Matsumoto ◽  
Masaki Takatsuka ◽  
Megumi Okuyama ◽  
Yuriko Ozeki ◽  
...  
Keyword(s):  
Cell Wall ◽  
Wall Structure ◽  
Regulation Mechanism ◽  
Mycolic Acids ◽  
Growth State ◽  
Cell Wall Assembly ◽  
Cell Wall Biogenesis ◽  
Covalently Linked ◽  
Mycobacterial Cell Wall ◽  
Wall Assembly

ABSTRACT Bacteria coordinate assembly of the cell wall as well as synthesis of cellular components depending on the growth state. The mycobacterial cell wall is dominated by mycolic acids covalently linked to sugars, such as trehalose and arabinose, and is critical for pathogenesis of mycobacteria. Transfer of mycolic acids to sugars is necessary for cell wall biogenesis and is mediated by mycolyltransferases, which have been previously identified as three antigen 85 (Ag85) complex proteins. However, the regulation mechanism which links cell wall biogenesis and the growth state has not been elucidated. Here we found that a histone-like protein has a dual concentration-dependent regulatory effect on mycolyltransferase functions of the Ag85 complex through direct binding to both the Ag85 complex and the substrate, trehalose-6-monomycolate, in the cell wall. A histone-like protein-deficient Mycobacterium smegmatis strain has an unusual crenellated cell wall structure and exhibits impaired cessation of glycolipid biosynthesis in the growth-retarded phase. Furthermore, we found that artificial alteration of the amount of the extracellular histone-like protein and the Ag85 complex changes the growth rate of mycobacteria, perhaps due to impaired down-regulation of glycolipid biosynthesis. Our results demonstrate novel regulation of cell wall assembly which has an impact on bacterial growth.

scholarly journals The mycobacterial cell wall partitions the plasma membrane to organize its own synthesis

2019 ◽  
Author(s):  
Alam García-Heredia ◽  
Takehiro Kado ◽  
Caralyn E. Sein ◽  
Julia Puffal ◽  
Sarah H. Osman ◽  
...  
Keyword(s):  
Cell Wall ◽  
Plasma Membrane ◽  
Membrane Domains ◽  
Peptidoglycan Biosynthesis ◽  
Cell Wall Assembly ◽  
Peptidoglycan Synthesis ◽  
Cell Wall Biogenesis ◽  
Mycobacterial Cell Wall ◽  
Wall Assembly ◽  
Made In

AbstractMany antibiotics target the assembly of cell wall peptidoglycan, an essential, heteropolymeric mesh that encases most bacteria. Different species have characteristic subcellular sites of peptidoglycan synthesis that they must carefully maintain for surface integrity and, ultimately, viability. In rod-shaped bacteria, cell wall elongation is spatially precise yet relies on a limited pool of lipid-linked precursors that generate and are attracted to membrane disorder. By tracking enzymes, substrates and products of peptidoglycan biosynthesis in Mycobacterium smegmatis, we show that precursors are made in plasma membrane domains that are laterally and biochemically distinct from sites of cell wall assembly. Membrane partitioning is required for robust, orderly peptidoglycan synthesis, indicating that these domains help template peptidoglycan synthesis. The cell wall-organizing protein DivIVA and the cell wall itself are essential for domain homeostasis. Thus, the peptidoglycan polymer feeds back on its membrane template to maintain an environment conducive to directional synthesis. We further show that our findings are applicable to rod-shaped bacteria that are phylogenetically distant from M. smegmatis, demonstrating that horizontal compartmentalization of precursors is a general feature of bacillary cell wall biogenesis.

scholarly journals An ABC transporter Wzm–Wzt catalyzes translocation of lipid-linked galactan across the plasma membrane in mycobacteria

2021 ◽  
Vol 118 (17) ◽  
pp. e2023663118
Author(s):  
Karin Savková ◽  
Stanislav Huszár ◽  
Peter Baráth ◽  
Zuzana Pakanová ◽  
Stanislav Kozmon ◽  
...  
Keyword(s):  
Cell Wall ◽  
Plasma Membrane ◽  
Abc Transporter ◽  
Morphological Changes ◽  
Transport Systems ◽  
Host Immune System ◽  
Mycolic Acids ◽  
Cell Wall Biogenesis ◽  
Covalently Linked ◽  
High Level

Mycobacterium tuberculosis, one of the deadliest pathogens in human history, is distinguished by a unique, multilayered cell wall, which offers the bacterium a high level of protection from the attacks of the host immune system. The primary structure of the cell wall core, composed of covalently linked peptidoglycan, branched heteropolysaccharide arabinogalactan, and mycolic acids, is well known, and numerous enzymes involved in the biosynthesis of its components are characterized. The cell wall biogenesis takes place at both cytoplasmic and periplasmic faces of the plasma membrane, and only recently some of the specific transport systems translocating the metabolic intermediates between these two compartments have been characterized [M. Jackson, C. M. Stevens, L. Zhang, H. I. Zgurskaya, M. Niederweis, Chem. Rev., 10.1021/acs.chemrev.0c00869 (2020)]. In this work, we use CRISPR interference methodology in Mycobacterium smegmatis to functionally characterize an ATP-binding cassette (ABC) transporter involved in the translocation of galactan precursors across the plasma membrane. We show that genetic knockdown of the transmembrane subunit of the transporter results in severe morphological changes and the accumulation of an aberrantly long galactan precursor. Based on similarities with structures and functions of specific O-antigen ABC transporters of gram-negative bacteria [C. Whitfield, D. M. Williams, S. D. Kelly, J. Biol. Chem. 295, 10593-10609 (2020)], we propose a model for coupled synthesis and export of the galactan polymer precursor in mycobacteria.

scholarly journals A cytoplasmic peptidoglycan amidase homologue controls mycobacterial cell wall synthesis

eLife ◽  
2016 ◽  
Vol 5 ◽  
Author(s):  
Cara C Boutte ◽  
Christina E Baer ◽  
Kadamba Papavinasasundaram ◽  
Weiru Liu ◽  
Michael R Chase ◽  
...  
Keyword(s):  
Cell Wall ◽  
Antibiotic Tolerance ◽  
Bacterial Survival ◽  
Cell Wall Metabolism ◽  
Cell Wall Assembly ◽  
Enzymatic Function ◽  
Precursor Synthesis ◽  
Mycobacterial Cell Wall ◽  
Wall Assembly ◽  
Multiple Antibiotics

Regulation of cell wall assembly is essential for bacterial survival and contributes to pathogenesis and antibiotic tolerance in Mycobacterium tuberculosis (Mtb). However, little is known about how the cell wall is regulated in stress. We found that CwlM, a protein homologous to peptidoglycan amidases, coordinates peptidoglycan synthesis with nutrient availability. Surprisingly, CwlM is sequestered from peptidoglycan (PG) by localization in the cytoplasm, and its enzymatic function is not essential. Rather, CwlM is phosphorylated and associates with MurA, the first enzyme in PG precursor synthesis. Phosphorylated CwlM activates MurA ~30 fold. CwlM is dephosphorylated in starvation, resulting in lower MurA activity, decreased cell wall metabolism, and increased tolerance to multiple antibiotics. A phylogenetic analysis of cwlM implies that localization in the cytoplasm drove the evolution of this factor. We describe a system that controls cell wall metabolism in response to starvation, and show that this regulation contributes to antibiotic tolerance.

scholarly journals FbpA-Dependent Biosynthesis of Trehalose Dimycolate Is Required for the Intrinsic Multidrug Resistance, Cell Wall Structure, and Colonial Morphology of Mycobacterium smegmatis

2005 ◽  
Vol 187 (19) ◽  
pp. 6603-6611 ◽  
Author(s):  
Liem Nguyen ◽  
Satheesh Chinnapapagari ◽  
Charles J. Thompson
Keyword(s):  
Cell Wall ◽  
Antibiotic Resistance ◽  
Mycobacterium Smegmatis ◽  
Mycolic Acid ◽  
Wall Structure ◽  
Single Mutation ◽  
Mycolic Acids ◽  
Trehalose Dimycolate ◽  
Colonial Morphology ◽  
Mycobacterial Cell Wall

ABSTRACT Ligation of mycolic acids to structural components of the mycobacterial cell wall generates a hydrophobic, impermeable barrier that provides resistance to toxic compounds such as antibiotics. Secreted proteins FbpA, FbpB, and FbpC attach mycolic acids to arabinogalactan, generating mycolic acid methyl esters (MAME) or trehalose, generating α,α′-trehalose dimycolate (TDM; also called cord factor). Our studies of Mycobacterium smegmatis showed that disruption of fbpA did not affect MAME levels but resulted in a 45% reduction of TDM. The fbpA mutant displayed increased sensitivity to both front-line tuberculosis-targeted drugs as well as other broad-spectrum antibiotics widely used for antibacterial chemotherapy. The irregular, hydrophobic surface of wild-type M. smegmatis colonies became hydrophilic and smooth in the mutant. While expression of M. smegmatis fbpA restored defects of the mutant, heterologous expression of the Mycobacterium tuberculosis fbpA gene was less effective. A single mutation in the M. smegmatis FbpA esterase domain inactivated its ability to provide antibiotic resistance. These data show that production of TDM by FbpA is essential for the intrinsic antibiotic resistance and normal colonial morphology of some mycobacteria and support the concept that FbpA-specific inhibitors, alone or in combination with other antibiotics, could provide an effective treatment to tuberculosis and other mycobacterial diseases.

scholarly journals Lcp1 Is a Phosphotransferase Responsible for Ligating Arabinogalactan to Peptidoglycan in Mycobacterium tuberculosis

mBio ◽  
2016 ◽  
Vol 7 (4) ◽  
Author(s):  
James Harrison ◽  
Georgina Lloyd ◽  
Maju Joe ◽  
Todd L. Lowary ◽  
Edward Reynolds ◽  
...  
Keyword(s):  
Cell Wall ◽  
Mycobacterium Tuberculosis ◽  
Essential Gene ◽  
Cell Envelope ◽  
New Drugs ◽  
Cell Wall Assembly ◽  
Mycobacterial Cell ◽  
Unique Cell ◽  
Mycobacterial Cell Wall ◽  
Wall Assembly

ABSTRACT Mycobacterium tuberculosis , the etiological agent of tuberculosis (TB), has a unique cell envelope which accounts for its unusual low permeability and contributes to resistance against common antibiotics. The main structural elements of the cell wall consist of a cross-linked network of peptidoglycan (PG) in which some of the muramic acid residues are covalently attached to a complex polysaccharide, arabinogalactan (AG), via a unique α- l -rhamnopyranose–(1→3)-α- d -GlcNAc-(1→P) linker unit. While the molecular genetics associated with PG and AG biosynthetic pathways have been largely delineated, the mechanism by which these two major pathways converge has remained elusive. In Gram-positive organisms, the LytR-CpsA-Psr (LCP) family of proteins are responsible for ligating cell wall teichoic acids to peptidoglycan, through a linker unit that bears a striking resemblance to that found in mycobacterial arabinogalactan. In this study, we have identified Rv3267 as a mycobacterial LCP homolog gene that encodes a phosphotransferase which we have named Lcp1. We demonstrate that lcp1 is an essential gene required for cell viability and show that recombinant Lcp1 is capable of ligating AG to PG in a cell-free radiolabeling assay. IMPORTANCE Tuberculosis is an infectious disease caused by the bacterial organism Mycobacterium tuberculosis . Survival of M. tuberculosis rests critically on the integrity of its unique cell wall; therefore, a better understanding of how the genes and enzymes involved in cell wall assembly work is fundamental for us to develop new drugs to treat this disease. In this study, we have identified Lcp1 as an essential phosphotransferase that ligates together arabinogalactan and peptidoglycan, two crucial cell wall macromolecules found within the mycobacterial cell wall. The discovery of Lcp1 sheds new light on the final stages of mycobacterial cell wall assembly and represents a key biosynthetic step that could be exploited for new anti-TB drug discovery.

Synthesis and anti-mycobacterial activity of glycosyl sulfamides of arabinofuranose

2016 ◽  
Vol 14 (5) ◽  
pp. 1748-1754 ◽  
Author(s):  
Kajitha Suthagar ◽  
Antony J. Fairbanks
Keyword(s):  
Cell Wall ◽  
Hydroxyl Group ◽  
Cell Wall Assembly ◽  
Mycobacterial Cell ◽  
Furanose Form ◽  
Mycobacterial Cell Wall ◽  
Wall Assembly

A series ofarabino N-glycosyl sulfamides, forced to adopt the furanose form by removal of the 5-hydroxyl group, were synthesised as putative isosteric mimics of decaprenolphosphoarabinose, the donor processed by arabinosyltransferases during mycobacterial cell wall assembly.

scholarly journals Membrane-partitioned cell wall synthesis in mycobacteria

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Alam García-Heredia ◽  
Takehiro Kado ◽  
Caralyn E Sein ◽  
Julia Puffal ◽  
Sarah H Osman ◽  
...  
Keyword(s):  
Cell Wall ◽  
Mycobacterium Smegmatis ◽  
General Feature ◽  
Membrane Domains ◽  
Peptidoglycan Biosynthesis ◽  
Cell Wall Assembly ◽  
Peptidoglycan Synthesis ◽  
Cell Wall Biogenesis ◽  
Wall Assembly ◽  
Made In

Many antibiotics target the assembly of cell wall peptidoglycan, an essential, heteropolymeric mesh that encases most bacteria. In rod-shaped bacteria, cell wall elongation is spatially precise yet relies on limited pools of lipid-linked precursors that generate and are attracted to membrane disorder. By tracking enzymes, substrates, and products of peptidoglycan biosynthesis in Mycobacterium smegmatis, we show that precursors are made in plasma membrane domains that are laterally and biochemically distinct from sites of cell wall assembly. Membrane partitioning likely contributes to robust, orderly peptidoglycan synthesis, suggesting that these domains help template peptidoglycan synthesis. The cell wall-organizing protein DivIVA and the cell wall itself promote domain homeostasis. These data support a model in which the peptidoglycan polymer feeds back on its membrane template to maintain an environment conducive to directional synthesis. Our findings are applicable to rod-shaped bacteria that are phylogenetically distant from M. smegmatis, indicating that horizontal compartmentalization of precursors may be a general feature of bacillary cell wall biogenesis.

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