scholarly journals Insight into the molecular basis of substrate recognition by the wall teichoic acid glycosyltransferase TagA

2021 ◽  
pp. 101464
Author(s):  
Orlando E. Martinez ◽  
Brendan J. Mahoney ◽  
Andrew K. Goring ◽  
Sung-Wook Yi ◽  
Denise P. Tran ◽  
...  
Keyword(s):  
Molecular Basis ◽  
Substrate Recognition ◽  
Teichoic Acid ◽  
Wall Teichoic Acid ◽  
Insight Into

scholarly journals Structure and mechanism ofStaphylococcus aureusTarM, the wall teichoic acid α-glycosyltransferase

2015 ◽  
Vol 112 (6) ◽  
pp. E576-E585 ◽  
Author(s):  
Solmaz Sobhanifar ◽  
Liam James Worrall ◽  
Robert J. Gruninger ◽  
Gregory A. Wasney ◽  
Markus Blaukopf ◽  
...  
Keyword(s):  
Teichoic Acid ◽  
Thick Layer ◽  
Wall Teichoic Acid ◽  
Acceptor Substrate ◽  
Gram Positive Bacteria ◽  
Bacterial Pathogenicity ◽  
Substrate Analog ◽  
Wall Teichoic Acids ◽  
Insight Into

Unique to Gram-positive bacteria, wall teichoic acids are anionic glycopolymers cross-stitched to a thick layer of peptidoglycan. The polyol phosphate subunits of these glycopolymers are decorated with GlcNAc sugars that are involved in phage binding, genetic exchange, host antibody response, resistance, and virulence. The search for the enzymes responsible for GlcNAcylation inStaphylococcus aureushas recently identified TarM and TarS with respective α- and β-(1–4) glycosyltransferase activities. The stereochemistry of the GlcNAc attachment is important in balancing biological processes, such that the interplay of TarM and TarS is likely important for bacterial pathogenicity and survival. Here we present the crystal structure of TarM in an unusual ternary-like complex consisting of a polymeric acceptor substrate analog, UDP from a hydrolyzed donor, and an α-glyceryl-GlcNAc product formed in situ. These structures support an internal nucleophilic substitution-like mechanism, lend new mechanistic insight into the glycosylation of glycopolymers, and reveal a trimerization domain with a likely role in acceptor substrate scaffolding.

scholarly journals Molecular basis for recognition of Listeria cell wall teichoic acid by the pseudo-symmetric SH3b-like repeats of a bacteriophage endolysin

2020 ◽  
Author(s):  
Yang Shen ◽  
Ioanna Kalograiaki ◽  
Alessio Prunotto ◽  
Matthew Dunne ◽  
Samy Boulos ◽  
...  
Keyword(s):  
Cell Wall ◽  
Molecular Basis ◽  
Teichoic Acid ◽  
Wall Teichoic Acid ◽  
Recognition Mechanism ◽  
Binding Domains ◽  
Cell Wall Binding ◽  
Binding Cavity ◽  
Carbohydrate Ligands ◽  
Van Der Waals Contacts

AbstractEndolysins are bacteriophage-encoded peptidoglycan hydrolases targeting the cell wall of host bacteria via their cell wall-binding domains (CBDs). The molecular basis for selective recognition of surface carbohydrate ligands by CBDs remains elusive. Here, we describe, in atomic detail, the interaction between the Listeria phage endolysin domain CBD500 and its cell wall teichoic acid (WTA) ligands. We show that 3’ O-acetylated GlcNAc residues integrated into the WTA polymer chain are the key epitope recognized by a CBD binding cavity located at the interface of tandem copies of beta-barrel, pseudo-symmetric SH3b-like repeats. This cavity consists of multiple aromatic residues making extensive interactions with two GlcNAc acetyl groups via hydrogen bonds and van der Waals contacts, while permitting the docking of the diastereomorphic ligands. The multidisciplinary approach described here delineates a previously unknown recognition mechanism by which a phage endolysin specifically recognizes and targets WTA, suggesting an adaptable model for regulation of endolysin specificity.

Insight Into The Molecular Basis Of The Anti‑Hyperglycemic Activity Of Ra‑3 In Type 2 Diabetic Rats And Its Cardioprotective Potential In Cultured Cardiomyoblasts

Metabolism ◽  
2021 ◽  
Vol 116 ◽  
pp. 154646
Author(s):  
R.A. Mosa ◽  
S.E. Mabhida ◽  
N.F. Sangweni ◽  
P.V. Dludla ◽  
A.R. Opoku ◽  
...  
Keyword(s):  
Molecular Basis ◽  
Diabetic Rats ◽  
Type 2 Diabetic ◽  
Insight Into

scholarly journals Depletion of Undecaprenyl Pyrophosphate Phosphatases Disrupts Cell Envelope Biogenesis in Bacillus subtilis

2016 ◽  
Vol 198 (21) ◽  
pp. 2925-2935 ◽  
Author(s):  
Heng Zhao ◽  
Yingjie Sun ◽  
Jason M. Peters ◽  
Carol A. Gross ◽  
Ethan C. Garner ◽  
...  
Keyword(s):  
Bacillus Subtilis ◽  
Transcriptional Repression ◽  
Cell Envelope ◽  
Turgor Pressure ◽  
Teichoic Acid ◽  
Lethal Gene ◽  
Genetic Redundancy ◽  
Wall Teichoic Acid ◽  
Content Type ◽  
Lipid Ii

ABSTRACTThe integrity of the bacterial cell envelope is essential to sustain life by countering the high turgor pressure of the cell and providing a barrier against chemical insults. InBacillus subtilis, synthesis of both peptidoglycan and wall teichoic acids requires a common C55lipid carrier, undecaprenyl-pyrophosphate (UPP), to ferry precursors across the cytoplasmic membrane. The synthesis and recycling of UPP requires a phosphatase to generate the monophosphate form Und-P, which is the substrate for peptidoglycan and wall teichoic acid synthases. Using an optimizedclusteredregularlyinterspacedshortpalindromicrepeat (CRISPR) system with catalytically inactive (“dead”)CRISPR-associated protein9(dCas9)-based transcriptional repression system (CRISPR interference [CRISPRi]), we demonstrate thatB. subtilisrequires either of two UPP phosphatases, UppP or BcrC, for viability. We show that a third predicted lipid phosphatase (YodM), with homology to diacylglycerol pyrophosphatases, can also support growth when overexpressed. Depletion of UPP phosphatase activity leads to morphological defects consistent with a failure of cell envelope synthesis and strongly activates the σM-dependent cell envelope stress response, includingbcrC, which encodes one of the two UPP phosphatases. These results highlight the utility of an optimized CRISPRi system for the investigation of synthetic lethal gene pairs, clarify the nature of theB. subtilisUPP-Pase enzymes, and provide further evidence linking the σMregulon to cell envelope homeostasis pathways.IMPORTANCEThe emergence of antibiotic resistance among bacterial pathogens is of critical concern and motivates efforts to develop new therapeutics and increase the utility of those already in use. The lipid II cycle is one of the most frequently targeted processes for antibiotics and has been intensively studied. Despite these efforts, some steps have remained poorly defined, partly due to genetic redundancy. CRISPRi provides a powerful tool to investigate the functions of essential genes and sets of genes. Here, we used an optimized CRISPRi system to demonstrate functional redundancy of two UPP phosphatases that are required for the conversion of the initially synthesized UPP lipid carrier to Und-P, the substrate for the synthesis of the initial lipid-linked precursors in peptidoglycan and wall teichoic acid synthesis.

scholarly journals Structural insight into the molecular mechanism of p53-mediated mitochondrial apoptosis

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Hudie Wei ◽  
Lingzhi Qu ◽  
Shuyan Dai ◽  
Yun Li ◽  
Haolan Wang ◽  
...  
Keyword(s):  
Molecular Basis ◽  
Mitochondrial Membrane ◽  
Ternary Complex ◽  
Mitochondrial Apoptosis ◽  
Tumor Suppressor P53 ◽  
Dimer Interface ◽  
Bona Fide ◽  
Structural Insight ◽  
Mitochondrial Membrane Permeabilization ◽  
Insight Into

AbstractThe tumor suppressor p53 is mutated in approximately half of all human cancers. p53 can induce apoptosis through mitochondrial membrane permeabilization by interacting with and antagonizing the anti-apoptotic proteins BCL-xL and BCL-2. However, the mechanisms by which p53 induces mitochondrial apoptosis remain elusive. Here, we report a 2.5 Å crystal structure of human p53/BCL-xL complex. In this structure, two p53 molecules interact as a homodimer, and bind one BCL-xL molecule to form a ternary complex with a 2:1 stoichiometry. Mutations at the p53 dimer interface or p53/BCL-xL interface disrupt p53/BCL-xL interaction and p53-mediated apoptosis. Overall, our current findings of the bona fide structure of p53/BCL-xL complex reveal the molecular basis of the interaction between p53 and BCL-xL, and provide insight into p53-mediated mitochondrial apoptosis.

scholarly journals Hidden Mode of Action of Glycopeptide Antibiotics: Inhibition of Wall Teichoic Acid Biosynthesis

2017 ◽  
Vol 121 (16) ◽  
pp. 3925-3932 ◽  
Author(s):  
Manmilan Singh ◽  
James Chang ◽  
Lauryn Coffman ◽  
Sung Joon Kim
Keyword(s):  
Mode Of Action ◽  
Teichoic Acid ◽  
Glycopeptide Antibiotics ◽  
Acid Biosynthesis ◽  
Wall Teichoic Acid

scholarly journals Localization and Interactions of Teichoic Acid Synthetic Enzymes in Bacillus subtilis

2007 ◽  
Vol 190 (5) ◽  
pp. 1812-1821 ◽  
Author(s):  
Alex Formstone ◽  
Rut Carballido-López ◽  
Philippe Noirot ◽  
Jeffery Errington ◽  
Dirk-Jan Scheffers
Keyword(s):  
Bacillus Subtilis ◽  
Cell Shape ◽  
Spatial Organization ◽  
Structural Integrity ◽  
Fluorescent Protein ◽  
Teichoic Acid ◽  
Cytoskeletal Proteins ◽  
Thick Wall ◽  
Wall Teichoic Acid ◽  
Critical Function

ABSTRACT The thick wall of gram-positive bacteria is a polymer meshwork composed predominantly of peptidoglycan (PG) and teichoic acids, both of which have a critical function in maintenance of the structural integrity and the shape of the cell. In Bacillus subtilis 168 the major teichoic acid is covalently coupled to PG and is known as wall teichoic acid (WTA). Recently, PG insertion/degradation over the lateral wall has been shown to occur in a helical pattern. However, the spatial organization of WTA assembly and its relationship with cell shape and PG assembly are largely unknown. We have characterized the localization of green fluorescent protein fusions to proteins involved in several steps of WTA synthesis in B. subtilis: TagB, -F, -G, -H, and -O. All of these localized similarly to the inner side of the cytoplasmic membrane, in a pattern strikingly similar to that displayed by probes of nascent PG. Helix-like localization patterns are often attributable to the morphogenic cytoskeletal proteins of the MreB family. However, localization of the Tag proteins did not appear to be substantially affected by single disruption of any of the three MreB homologues of B. subtilis. Bacterial and yeast two-hybrid experiments revealed a complex network of interactions involving TagA, -B, -E, -F, -G, -H, and -O and the cell shape determinants MreC and MreD (encoded by the mreBCD operon and presumably involved in the spatial organization of PG synthesis). Taken together, our results suggest that, in B. subtilis at least, the synthesis and export of WTA precursors are mediated by a large multienzyme complex that may be associated with the PG-synthesizing machinery.

scholarly journals Analysis of phage-resistant mechanisms inStaphylococcus aureusSA003 reveals a different binding mechanism for the closely related Twort-like phages ϕSA012 and ϕSA039

2018 ◽  
Author(s):  
Aa Haeruman Azam ◽  
Fumiya Hoshiga ◽  
Ippei Takeuchi ◽  
Kazuhiko Miyanaga ◽  
Yasunori Tanji
Keyword(s):  
Teichoic Acid ◽  
Point Mutations ◽  
In Silico Analysis ◽  
Close Relative ◽  
Phenotypic Change ◽  
Missense Mutations ◽  
Wild Type ◽  
Wall Teichoic Acid ◽  
Whole Genome Analysis ◽  
Specific Phage

ABSTRACTWe have previously generated strains ofStaphylococcus aureusSA003 resistant to its specific phage ϕSA012 through long-term coevolution experiment. However, the DNA mutations responsible for the phenotypic change of phage resistance are unknown. Whole-genome analysis revealed six genes that acquired unique point mutations: five missense mutations and one nonsense mutation. Moreover, one deletion, 1.779-bp, resulted in the deletion of the genes encoding glycosyltransferase, TarS, and iron-sulfure repair protein, ScdA. The deletion occurred from the second round of coculture (SA003R2) and remained through the last round. The ϕSA012 infection toward SA003R2 had decreased to 79.77±7.50% according to plating efficiency. Complementation of the phage-resistant strain by the wild-type allele showed two mutated host genes were linked to the inhibition of post-adsorption, and five genes were linked to phage adsorption of ϕSA012. Unlike ϕSA012, infection by ϕSA039, a close relative of ϕSA012, onto SA003R2 was impaired drastically. Complementation of SA003R2 by wild-typetarSrestores the infectivity of ϕSA039. Thus, we concluded that ϕSA039 requires β-GlcNAc in Wall Teichoic Acid (WTA) for its binding. In silico analysis of the ϕSA039 genome revealed that several proteins in the tail and baseplate region were different from ϕSA012; notably the partial deletion oforf96of ϕSA039, a homolog oforf99of ϕSA012.Orf100of ϕSA039, a homolog ofOrf103of ϕSA012, a previously reported receptor binding protein (RBP), had low similarity (86%) to that of ϕSA012. The difference in tail and baseplate proteins might be the factor for specificity difference between ϕSA012 and ϕSA039.

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