scholarly journals Molecular basis of Streptococcus mutans sortase A inhibition by the flavonoid natural product trans-chalcone

2015 ◽  
Vol 51 (52) ◽  
pp. 10483-10485 ◽  
Author(s):  
Daynea J. Wallock-Richards ◽  
Jon Marles-Wright ◽  
David J. Clarke ◽  
Amarnath Maitra ◽  
Michael Dodds ◽  
...  
Keyword(s):  
Cell Wall ◽  
Natural Product ◽  
Streptococcus Mutans ◽  
Molecular Basis ◽  
Surface Proteins ◽  
Sortase A ◽  
Gram Positive

Sortase A (SrtA) from Gram positive pathogens is an attractive target for inhibitors due to its role in the attachment of surface proteins to the cell wall.

Covalent Sortase A Inhibitor ML346 Prevents Staphylococcus aureus Infection of Galleria mellonella

2021 ◽  
Author(s):  
Xiang-Na Guan ◽  
Tao Zhang ◽  
Teng Yang ◽  
Ze Dong ◽  
Song Yang ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Cell Wall ◽  
Galleria Mellonella ◽  
Surface Proteins ◽  
Sortase A ◽  
Gram Positive ◽  
Gram Positive Bacteria ◽  
Aureus Infection ◽  
Cell Wall Peptidoglycan

The housekeeping sortase A (SrtA), a membrane-associated cysteine transpeptidase, is responsible for anchoring surface proteins to the cell wall peptidoglycan in Gram-positive bacteria. This process is essential for the regulation...

scholarly journals Novel Sortase A Inhibitors to Counteract Gram-Positive Bacterial Biofilms

Proceedings ◽  
2019 ◽  
Vol 22 (1) ◽  
pp. 23
Author(s):  
Maria Valeria Raimondi ◽  
Roberta Listro ◽  
Maria Grazia Cusimano ◽  
Mery La Franca ◽  
Teresa Faddetta ◽  
...  
Keyword(s):  
Cell Wall ◽  
Surface Proteins ◽  
Bacterial Biofilms ◽  
Sortase A ◽  
Gram Positive ◽  
Gram Positive Bacteria ◽  
Membrane Enzyme

Sortase A (SrtA) is a membrane enzyme responsible for the covalent anchoring of surface proteins on the cell wall of Gram-positive bacteria. [...]

scholarly journals Sorting out the Superbugs: Potential of Sortase A Inhibitors among Other Antimicrobial Strategies to Tackle the Problem of Antibiotic Resistance

Antibiotics ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 164 ◽  
Author(s):  
Nikita Zrelovs ◽  
Viktorija Kurbatska ◽  
Zhanna Rudevica ◽  
Ainars Leonchiks ◽  
Davids Fridmanis
Keyword(s):  
Cell Wall ◽  
Antibiotic Resistance ◽  
Pathogenic Bacteria ◽  
Resistance Mechanisms ◽  
Surface Proteins ◽  
Sortase A ◽  
Inhibitory Compounds ◽  
Alternative Means ◽  
Alternative Approaches ◽  
Conventional Antibiotics

Rapid spread of antibiotic resistance throughout the kingdom bacteria is inevitably bringing humanity towards the “post-antibiotic” era. The emergence of so-called “superbugs”—pathogen strains that develop resistance to multiple conventional antibiotics—is urging researchers around the globe to work on the development or perfecting of alternative means of tackling the pathogenic bacteria infections. Although various conceptually different approaches are being considered, each comes with its advantages and drawbacks. While drug-resistant pathogens are undoubtedly represented by both Gram(+) and Gram(−) bacteria, possible target spectrum across the proposed alternative approaches of tackling them is variable. Numerous anti-virulence strategies aimed at reducing the pathogenicity of target bacteria rather than eliminating them are being considered among such alternative approaches. Sortase A (SrtA) is a membrane-associated cysteine protease that catalyzes a cell wall sorting reaction by which surface proteins, including virulence factors, are anchored to the bacterial cell wall of Gram(+) bacteria. Although SrtA inhibition seems perspective among the Gram-positive pathogen-targeted antivirulence strategies, it still remains less popular than other alternatives. A decrease in virulence due to inactivation of SrtA activity has been extensively studied in Staphylococcus aureus, but it has also been demonstrated in other Gram(+) species. In this manuscript, results of past studies on the discovery of novel SrtA inhibitory compounds and evaluation of their potency were summarized and commented on. Here, we discussed the rationale behind the inhibition of SrtA, raised some concerns on the comparability of the results from different studies, and touched upon the possible resistance mechanisms as a response to implementation of such therapy in practice. The goal of this article is to encourage further studies of SrtA inhibitory compounds.

scholarly journals Structures of the surface exposed proteins of Gram positive bacteria

2014 ◽  
Vol 70 (a1) ◽  
pp. C432-C432
Author(s):  
George Minasov ◽  
Salvatore Nocadello ◽  
Ekaterina Filippova ◽  
Andrei Halavaty ◽  
Wayne Anderson
Keyword(s):  
Cell Wall ◽  
Infectious Diseases ◽  
Bacillus Anthracis ◽  
Structural Genomics ◽  
Drug Targets ◽  
Morphological Changes ◽  
Target Selection ◽  
Surface Proteins ◽  
Human Pathogens ◽  
Gram Positive

The Center for Structural Genomics for Infectious Diseases (CSGID) applies structural genomics approaches to biomedically important proteins from human pathogens. It also provides the infectious disease community with a high throughput pipeline for structure determination that carries out all steps of the process, from target selection through structure deposition. Target proteins include drug targets, essential enzymes, virulence factors and vaccine candidates. The CSGID has deposited over 680 structures in the Protein Data Bank. The proteins that are exposed on the surface of Gram positive bacterial pathogens (including Staphylococcus aureus, Bacillus anthracis, Listeria monocytogenes, Streptococcus species and Clostridium species) have been one focus area for the CSGID. So far, the structures of more than 55 of these proteins have been determined. The surface proteins are important in the interactions between the pathogen and its host, but many of them are as yet functionally uncharacterized. Among the examples that will be presented is the Bacillus anthracis SpoIID protein. SpoIID is part of a coordinated cell wall degradation machine that is essential for sporulation and the morphological changes involved. It represents a new family of lytic transglycosylases that degrade the glycan strands of the peptidoglycan cell wall. The two active site clefts in the dimeric enzyme include residues from both subunits, suggesting that the dimer is required for activity. This project has been funded in whole or in part with Federal funds from the National Institute of Allergy and Infectious Diseases, National Institutes of Health, Department of Health and Human Services, under Contracts No. HHSN272200700058C and HHSN272201200026C.

scholarly journals A Comparative Genome Analysis Identifies Distinct Sorting Pathways in Gram-Positive Bacteria

2004 ◽  
Vol 72 (5) ◽  
pp. 2710-2722 ◽  
Author(s):  
David Comfort ◽  
Robert T. Clubb
Keyword(s):  
Staphylococcus Aureus ◽  
Cell Wall ◽  
Surface Proteins ◽  
Sequence Motifs ◽  
Comparative Genome Analysis ◽  
Gram Positive ◽  
Microbial Genomes ◽  
Searchable Database ◽  
Gram Positive Bacteria ◽  
Related Proteins

ABSTRACT Surface proteins in gram-positive bacteria are frequently required for virulence, and many are attached to the cell wall by sortase enzymes. Bacteria frequently encode more than one sortase enzyme and an even larger number of potential sortase substrates that possess an LPXTG-type cell wall sorting signal. In order to elucidate the sorting pathways present in gram-positive bacteria, we performed a comparative analysis of 72 sequenced microbial genomes. We show that sortase enzymes can be partitioned into five distinct subfamilies based upon their primary sequences and that most of their substrates can be predicted by making a few conservative assumptions. Most bacteria encode sortases from two or more subfamilies, which are predicted to function nonredundantly in sorting proteins to the cell surface. Only ∼20% of sortase-related proteins are most closely related to the well-characterized Staphylococcus aureus SrtA protein, but nonetheless, these proteins are responsible for anchoring the majority of surface proteins in gram-positive bacteria. In contrast, most sortase-like proteins are predicted to play a more specialized role, with each anchoring far fewer proteins that contain unusual sequence motifs. The functional sortase-substrate linkage predictions are available online (http://www.doe-mbi.ucla.edu/Services/Sortase/ ) in a searchable database.

scholarly journals Astilbin Inhibits the Activity of Sortase A from Streptococcus mutans

Molecules ◽  
2019 ◽  
Vol 24 (3) ◽  
pp. 465 ◽  
Author(s):  
Junxian Wang ◽  
Yan Shi ◽  
Shisong Jing ◽  
Haisi Dong ◽  
Dacheng Wang ◽  
...  
Keyword(s):  
Dental Caries ◽  
Streptococcus Mutans ◽  
Biofilm Formation ◽  
Cell Attachment ◽  
Surface Proteins ◽  
Dynamics Simulation ◽  
Sortase A ◽  
Acid Fermentation ◽  
Host Cell Attachment ◽  
Potent Inhibitory Activity

Streptococcus mutans (S. mutans) is the primary etiological agent of dental caries. The S. mutans enzyme sortase A (SrtA) is responsible for anchoring bacterial cell wall surface proteins involved in host cell attachment and biofilm formation. Thus, SrtA is an attractive target for inhibiting dental caries caused by S. mutans-associated acid fermentation. In this study, we observed that astilbin, a flavanone compound extracted from Rhizoma Smilacis Glabrae, has potent inhibitory activity against the S. mutans SrtA, with an IC50 of 7.5 μg/mL. In addition, astilbin was proven to reduce the formation of biofilm while without affecting the growth of S. mutans. The results of a molecular dynamics simulation and a mutation analysis revealed that the Arg213, Leu111, and Leu116 of SrtA are important for the interaction between SrtA and astilbin. The results of this study demonstrate the potential of using astilbin as a nonbactericidal agent to modulate pathogenicity of S. mutans by inhibiting the activity of SrtA.

scholarly journals Anchor Structure of Staphylococcal Surface Proteins

2005 ◽  
Vol 280 (16) ◽  
pp. 16263-16271 ◽  
Author(s):  
Luciano A. Marraffini ◽  
Olaf Schneewind
Keyword(s):  
Cell Wall ◽  
Surface Protein ◽  
Surface Proteins ◽  
Sortase A ◽  
Carboxyl Group ◽  
Amino Group ◽  
Sorting Signal ◽  
Lipid Ii ◽  
Sorting Signals ◽  
Anchor Structure

Staphylococcus aureussortase A cleaves surface protein precursors bearing C-terminal LPXTG motif sorting signals between the threonine and glycine residues. Using lipid II precursor as cosubstrate, sortase A catalyzes the amide linkage between the carboxyl group of threonine and the amino group of pentaglycine cross-bridges, thereby tethering C-terminal ends of surface proteins to the bacterial cell wall envelope. Staphylococcal sortase B also anchors its only known substrate, the IsdC precursor with a C-terminal NPQTN motif sorting signal, to the cell wall envelope. Herein, we determined the cell wall anchor structure of IsdC. The sorting signal of IsdC is cleaved between threonine and asparagine of the NPQTN motif, and the carboxyl group of threonine is amide-linked to the amino group of pentaglycine crossbridges. In contrast to sortase A substrates, the anchor structure of IsdC displays shorter glycan strands and significantly less cell wall cross-linking. A model is proposed whereby sortases A and B recognize unique features of sorting signals and peptidoglycan substrates to deposit proteins with distinct topologies in the cell wall envelope.

scholarly journals Structure and Mechanism of LcpA, a Phosphotransferase That Mediates Glycosylation of a Gram-Positive Bacterial Cell Wall-Anchored Protein

mBio ◽  
2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Sara D. Siegel ◽  
Brendan R. Amer ◽  
Chenggang Wu ◽  
Michael R. Sawaya ◽  
Jason E. Gosschalk ◽  
...  
Keyword(s):  
Cell Wall ◽  
Disulfide Bond ◽  
Cell Envelope ◽  
Teichoic Acid ◽  
Surface Proteins ◽  
Wall Teichoic Acid ◽  
Gram Positive ◽  
Content Type ◽  
X Ray Crystallography ◽  
Gram Positive Bacteria

ABSTRACT The widely conserved LytR-CpsA-Psr (LCP) family of enzymes in Gram-positive bacteria is known to attach glycopolymers, including wall teichoic acid, to the cell envelope. However, it is undetermined if these enzymes are capable of catalyzing glycan attachment to surface proteins. In the actinobacterium Actinomyces oris, an LCP homolog here named LcpA is genetically linked to GspA, a glycoprotein that is covalently attached to the bacterial peptidoglycan by the housekeeping sortase SrtA. Here we show by X-ray crystallography that LcpA adopts an α-β-α structural fold, akin to the conserved LCP domain, which harbors characteristic catalytic arginine residues. Consistently, alanine substitution for these residues, R149 and R266, abrogates GspA glycosylation, leading to accumulation of an intermediate form termed GspALMM, which is also observed in the lcpA mutant. Unlike other LCP proteins characterized to date, LcpA contains a stabilizing disulfide bond, mutations of which severely affect LcpA stability. In line with the established role of disulfide bond formation in oxidative protein folding in A. oris, deletion of vkor, coding for the thiol-disulfide oxidoreductase VKOR, also significantly reduces LcpA stability. Biochemical studies demonstrated that the recombinant LcpA enzyme possesses pyrophosphatase activity, enabling hydrolysis of diphosphate bonds. Furthermore, this recombinant enzyme, which weakly interacts with GspA in solution, catalyzes phosphotransfer to GspALMM. Altogether, the findings support that A. oris LcpA is an archetypal LCP enzyme that glycosylates a cell wall-anchored protein, a process that may be conserved in Actinobacteria, given the conservation of LcpA and GspA in these high-GC-content organisms. IMPORTANCE In Gram-positive bacteria, the conserved LCP family enzymes studied to date are known to attach glycopolymers, including wall teichoic acid, to the cell envelope. It is unknown if these enzymes catalyze glycosylation of surface proteins. We show here in the actinobacterium Actinomyces oris by X-ray crystallography and biochemical analyses that A. oris LcpA is an LCP homolog, possessing pyrophosphatase and phosphotransferase activities known to belong to LCP enzymes that require conserved catalytic Arg residues, while harboring a unique disulfide bond critical for protein stability. Importantly, LcpA mediates glycosylation of the surface protein GspA via phosphotransferase activity. Our studies provide the first experimental evidence of an archetypal LCP enzyme that promotes glycosylation of a cell wall-anchored protein in Gram-positive bacteria.

scholarly journals Roles of Sortase in Surface Expression of the Major Protein Adhesin P1, Saliva-Induced Aggregation and Adherence, and Cariogenicity of Streptococcus mutans

2003 ◽  
Vol 71 (2) ◽  
pp. 676-681 ◽  
Author(s):  
Song F. Lee ◽  
Thomas L. Boran
Keyword(s):  
Cell Wall ◽  
Amino Acid ◽  
Streptococcus Mutans ◽  
Tetracycline Resistance ◽  
Surface Expression ◽  
Surface Proteins ◽  
Major Protein ◽  
Wild Type ◽  
Hydrophobic Domain ◽  
Induced Aggregation

ABSTRACT Sortase is a newly discovered transpeptidase that covalently links LPXTGX-containing surface proteins to the gram-positive bacterial cell wall. In this study, the sortase gene (srtA) was isolated from Streptococcus mutans NG8 by PCR. The gene encoded a 246-amino-acid protein, including a 40-amino-acid signal peptide. The srtA gene was insertionally inactivated by a tetracycline resistance cassette. P1, a major surface protein adhesin previously shown to anchor to the peptidoglycan by the LPXTGX motif, was secreted into the culture medium by the srtA mutant. In contrast, the wild-type P1 remained cell wall associated. Complementation of the mutant with srtA restored the P1 surface expression phenotype. P1 produced by the mutant, but not that produced by the wild type and the srtA-complemented mutant, was recognized by an antibody raised against the hydrophobic domain and charged tail C terminal to the LPXTGX motif. These results suggest that the failure to anchor P1 to the cell wall is due to the lack of cleavage of P1 at the LPXTGX motif. The srtA mutant was markedly less hydrophobic than the wild type and the complemented mutant. The srtA mutant failed to aggregate in the presence of saliva or salivary agglutinin and adhered poorly to saliva- or salivary agglutinin-coated hydroxylapatite. In rats, the srtA mutant colonized the teeth poorly when sucrose was absent. When sucrose was present, the srtA mutant colonized the teeth but less effectively and induced significantly less caries (P < 0.05) than the wild-type strain. In conclusion, the sortase enzyme in S. mutans is responsible for anchoring P1 to the cell surface and plays a role in modulating the surface properties and cariogenicity of S. mutans.

scholarly journals Entropy-driven translocation of disordered proteins through the Gram-positive bacterial cell wall

2020 ◽  
Author(s):  
David K. Halladin ◽  
Fabian E. Ortega ◽  
Katharine M. Ng ◽  
Matthew J. Footer ◽  
Nenad S. Mitić ◽  
...  
Keyword(s):  
Cell Wall ◽  
Outer Surface ◽  
Bacterial Cell ◽  
Surface Proteins ◽  
Disordered Proteins ◽  
Nuclear Pore ◽  
Bacterial Membrane ◽  
Gram Positive ◽  
Intrinsically Disordered ◽  
Disordered Protein

Cells across all kingdoms of life actively partition molecules between discrete cellular compartments. In Gram-positive bacteria, a thick and highly cross-linked peptidoglycan cell wall separates the bacterial membrane from the extracellular space, imposing a barrier that must be crossed by proteins whose functions require that they be exposed on the bacterial cell surface1,2. Some surface-exposed proteins, such as the Listeria monocytogenes actin nucleation-promoting factor ActA3, remain associated with the bacterial membrane yet somehow thread through tens of nanometers of dense, cross-linked cell wall to expose their N-terminus on the outer surface4,5. Here, we show that entropy can drive the translocation of disordered transmembrane proteins through the Gram-positive cell wall. We develop a physical model predicting that the entropic constraint imposed by a thin periplasm is sufficient to drive translocation of an intrinsically disordered protein like ActA across a porous barrier similar to the cell wall. Consistent with this scenario, we demonstrate experimentally that translocation depends on both the dimensions of the cell envelope and the length of the disordered protein, and that translocation is reversible. We also show that disordered regions from eukaryotic nuclear pore complex proteins are capable of entropy-driven translocation through Gram-positive cell walls. These observations suggest that entropic forces alone, rather than chaperones or chemical energy, are sufficient to drive translocation of certain Gram-positive surface proteins for exposure on the outer surface of the cell wall.

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