scholarly journals Cell-wall synthesis and ribosome maturation are co-regulated by an RNA switch in Mycobacterium tuberculosis

2018 ◽  
Vol 46 (11) ◽  
pp. 5837-5849 ◽  
Author(s):  
Stefan Schwenk ◽  
Alexandra Moores ◽  
Irene Nobeli ◽  
Timothy D McHugh ◽  
Kristine B Arnvig
Keyword(s):  
Cell Wall ◽  
Mycobacterium Tuberculosis ◽  
Cell Wall Synthesis ◽  
Rna Switch

scholarly journals Cell-wall synthesis and ribosome maturation are co-regulated by an RNA switch in Mycobacterium tuberculosis

2017 ◽  
Author(s):  
Stefan Schwenk ◽  
Alexandra Moores ◽  
Irene Nobeli ◽  
Timothy D. McHugh ◽  
Kristine B. Arnvig
Keyword(s):  
Cell Wall ◽  
Mycobacterium Tuberculosis ◽  
Regulatory Element ◽  
Start Codon ◽  
Cell Wall Synthesis ◽  
Active Growth ◽  
Methyl Transferase ◽  
Latent Tb ◽  
Latent Tb Infection ◽  
Rna Switch

AbstractThe success of Mycobacterium tuberculosis as a pathogen relies on the ability to switch between active growth and non-replicating persistence, associated with latent TB infection. Resuscitation promoting factors (Rpfs) are essential for the transition of M. tuberculosis to dormancy and for emergence from the non-replicating persistent state. But these enzymes are double-edged swords, as their ability to degrade the cell wall, is potentially lethal to the bacterium itself. Hence, Rpf expression is tightly regulated. We have identified a novel regulatory element in the 5’ untranslated region (UTR) of rpfB. We demonstrate that this element is a transcriptionally regulated RNA switch/riboswitch candidate, which is restricted to pathogenic mycobacteria, suggesting a role in virulence. Moreover, we have used translation start site mapping to re-annotate the RpfB start codon and identified and validated a ribosome binding site that is likely to be targeted by an RpfB antisense RNA. Finally, we show that rpfB is co-transcribed with downstream genes, ksgA and ispE. ksgA encodes a universally conserved methyl transferase involved in ribosome maturation and ispE encodes an essential ATP-dependent kinase involved in cell wall synthesis. This arrangement implies co-regulation of resuscitation, cell wall synthesis and ribosome maturation via the RNA switch. We propose that deregulation of this switch, associated with cell wall synthesis and ribosome function, presents a new target for anti-tuberculosis drug development.ImportanceThis work describes the identification and characterisation of a novel regulatory RNA element/attenuator that controls cell wall synthesis and ribosome function in Mycobacterium tuberculosis, the causative agent of human tuberculosis (TB). By switching between two different conformations, this RNA switch can either enable or inhibit transcription of a tri-cistronic mRNA that encodes a cell-wall remodelling enzyme crucial for activation of latent TB, an RNA methytransferase that is important for ribosome function and a protein kinase essential for early steps in cell wall synthesis. This RNA switch is only present in a subset of pathogenic mycobacteria, and by regulating the expression of three genes associated with classical antimicrobial targets we believe that it offers a novel important target for future anti-tuberculosis drugs.

scholarly journals Drug Targeting Mycobacterium tuberculosis Cell Wall Synthesis: Development of a Microtiter Plate-Based Screen for UDP-Galactopyranose Mutase and Identification of an Inhibitor from a Uridine-Based Library

2003 ◽  
Vol 47 (1) ◽  
pp. 378-382 ◽  
Author(s):  
Michael S. Scherman ◽  
Katharine A. Winans ◽  
Richard J. Stern ◽  
Victoria Jones ◽  
Carolyn R. Bertozzi ◽  
...  
Keyword(s):  
Cell Wall ◽  
Mycobacterium Tuberculosis ◽  
Drug Targeting ◽  
Enzyme Inhibitor ◽  
Microtiter Plate ◽  
Biosynthetic Enzyme ◽  
Cell Wall Synthesis ◽  
Chemical Library ◽  
Microtiter Plate Assay ◽  
Plate Assay

ABSTRACT A microtiter plate assay for UDP-galactopyranose mutase, an essential cell wall biosynthetic enzyme of Mycobacterium tuberculosis, was developed. The assay is based on the release of tritiated formaldehyde from UDP-galactofuranose but not UDP-galactopyranose by periodate and was used to identify a uridine-based enzyme inhibitor from a chemical library.

scholarly journals Mycobacterium tuberculosis CwsA Interacts with CrgA and Wag31, and the CrgA-CwsA Complex Is Involved in Peptidoglycan Synthesis and Cell Shape Determination

2012 ◽  
Vol 194 (23) ◽  
pp. 6398-6409 ◽  
Author(s):  
P. Plocinski ◽  
N. Arora ◽  
K. Sarva ◽  
E. Blaszczyk ◽  
H. Qin ◽  
...  
Keyword(s):  
Cell Wall ◽  
Mycobacterium Tuberculosis ◽  
Mutant Strain ◽  
Cell Shape ◽  
Double Mutant ◽  
Bacterial Cell Division ◽  
Cell Wall Synthesis ◽  
Content Type ◽  
Ring Assembly ◽  
Double Mutant Strain

ABSTRACTBacterial cell division and cell wall synthesis are highly coordinated processes involving multiple proteins. Here, we show that Rv0008c, a novel small membrane protein fromMycobacterium tuberculosis, localizes to the poles and on membranes and shows an overall punctate localization throughout the cell. Furthermore, Rv0008c interacts with two proteins, CrgA and Wag31, implicated in peptidoglycan (PG) synthesis in mycobacteria. Deletion of the Rv0008c homolog inM. smegmatis, MSMEG_0023, caused bulged cell poles, formation of rounded cells, and defects in polar localization of Wag31 and cell wall synthesis, with cell wall synthesis measured by the incorporation of the [14C]N-acetylglucosamine cell wall precursor. TheM. smegmatisMSMEG_0023crgAdouble mutant strain showed severe defects in growth, viability, cell wall synthesis, cell shape, and the localization of the FtsZ, FtsI, and Wag31 proteins. The double mutant strain also exhibited increased autolytic activity in the presence of detergents. Because CrgA and Wag31 proteins interact with FtsI individually, we believe that regulated cell wall synthesis and cell shape maintenance require the concerted actions of the CrgA, Rv0008c, FtsI, and Wag31 proteins. We propose that, together, CrgA and Rv0008c, renamed CwsA forcellwall synthesis and cellshape proteinA, play crucial roles in septal and polar PG synthesis and help coordinate these processes with the FtsZ-ring assembly in mycobacteria.

ubiA (Rv3806c) encoding DPPR synthase involved in cell wall synthesis is associated with ethambutol resistance in Mycobacterium tuberculosis

Tuberculosis ◽  
2015 ◽  
Vol 95 (2) ◽  
pp. 149-154 ◽  
Author(s):  
Lei He ◽  
Xiaobo Wang ◽  
Peng Cui ◽  
Jialin Jin ◽  
Jiazhen Chen ◽  
...  
Keyword(s):  
Cell Wall ◽  
Mycobacterium Tuberculosis ◽  
Cell Wall Synthesis

scholarly journals Galactosyl Transferases in Mycobacterial Cell Wall Synthesis

2007 ◽  
Vol 190 (3) ◽  
pp. 1141-1145 ◽  
Author(s):  
Martina Beláňová ◽  
Petronela Dianišková ◽  
Patrick J. Brennan ◽  
Gladys C. Completo ◽  
Natisha L. Rose ◽  
...  
Keyword(s):  
Cell Wall ◽  
Mycobacterium Tuberculosis ◽  
Mycobacterium Smegmatis ◽  
Cell Wall Synthesis ◽  
Mycobacterial Cell ◽  
Mycobacterial Cell Wall ◽  
Natural And Synthetic

ABSTRACT Two galactosyl transferases can apparently account for the full biosynthesis of the cell wall galactan of mycobacteria. Evidence is presented based on enzymatic incubations with purified natural and synthetic galactofuranose (Galf) acceptors that the recombinant galactofuranosyl transferase, GlfT1, from Mycobacterium smegmatis, the Mycobacterium tuberculosis Rv3782 ortholog known to be involved in the initial steps of galactan formation, harbors dual β-(1→4) and β-(1→5) Galf transferase activities and that the product of the enzyme, decaprenyl-P-P-GlcNAc-Rha-Galf-Galf, serves as a direct substrate for full polymerization catalyzed by another bifunctional Galf transferase, GlfT2, the Rv3808c enzyme.

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