Synthesis and anti-mycobacterial activity of glycosyl sulfamides of arabinofuranose

2016 ◽  
Vol 14 (5) ◽  
pp. 1748-1754 ◽  
Author(s):  
Kajitha Suthagar ◽  
Antony J. Fairbanks

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.

mBio ◽  
2016 ◽  
Vol 7 (4) ◽  
Author(s):  
James Harrison ◽  
Georgina Lloyd ◽  
Maju Joe ◽  
Todd L. Lowary ◽  
Edward Reynolds ◽  
...  

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.


eLife ◽  
2016 ◽  
Vol 5 ◽  
Author(s):  
Cara C Boutte ◽  
Christina E Baer ◽  
Kadamba Papavinasasundaram ◽  
Weiru Liu ◽  
Michael R Chase ◽  
...  

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.


2019 ◽  
Author(s):  
Alam García-Heredia ◽  
Takehiro Kado ◽  
Caralyn E. Sein ◽  
Julia Puffal ◽  
Sarah H. Osman ◽  
...  

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.


2007 ◽  
Vol 189 (22) ◽  
pp. 8241-8249 ◽  
Author(s):  
Tomoya Katsube ◽  
Sohkichi Matsumoto ◽  
Masaki Takatsuka ◽  
Megumi Okuyama ◽  
Yuriko Ozeki ◽  
...  

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.


Yeast ◽  
2021 ◽  
Author(s):  
Qingguo Guo ◽  
Na Meng ◽  
Guanzhi Fan ◽  
Dong Sun ◽  
Yuan Meng ◽  
...  

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