The Lasso Peptide Siamycin-I Targets Lipid II at the Gram-Positive Cell Surface

2019 ◽  
Vol 14 (5) ◽  
pp. 966-974 ◽  
Author(s):  
Stephanie Tan ◽  
Kevin C. Ludwig ◽  
Anna Müller ◽  
Tanja Schneider ◽  
Justin R. Nodwell
2021 ◽  
Author(s):  
Lydia Stariha ◽  
Dewey G. McCafferty

<p>Lasso peptides are a structurally diverse superfamily of</p><p>conformationally-constrained peptide natural products, of which a</p><p>subset exhibits broad antimicrobial activity. Although advances in</p><p>bioinformatics have increased our knowledge of strains harboring</p><p>the biosynthetic machinery for lasso peptide production, relating</p><p>peptide sequence to bioactivity remains a continuous challenge.</p><p>Towards this end, a structure-driven genome mining investigation</p><p>of Actinobacteria-produced antimicrobial lasso peptides was</p><p>performed to correlate predicted primary structure with antibiotic</p><p>activity. Bioinformatic evaluation revealed eight putative novel</p><p>class I lasso peptide sequences. This subset is predicted to</p><p>possess antibiotic activity as characterized members of this class</p><p>have both broad spectrum and potent activity against Gram positive</p><p>strains. Fermentation of one of these hits, Streptomyces</p><p>NRRL F-5639, resulted in the production of a novel class I lasso</p><p>peptide, arcumycin, named for the Latin word for bow or arch,</p><p>arcum. Arcumycin exhibited antibiotic activity against Gram positive</p><p>bacteria including <i>Bacillus subtilis</i> (4 μg/mL),</p><p><i>Staphylococcus aureus </i>(8 μg/mL), and <i>Micrococcus luteus</i> (8</p><p>μg/mL). Arcumycin treatment of <i>B. subtilis</i> liaI-β-gal promoter</p><p>fusion reporter strain resulted in upregulation of the system liaRS</p><p>by the promoter liaI, indicating arcumycin interferes with lipid II</p><p>biosynthesis. Cumulatively, the results illustrate the relationship</p><p>between phylogenetically related lasso peptides and their</p><p>bioactivity as validated through the isolation, structural</p><p>determination, and evaluation of bioactivity of the novel class I</p><p>antimicrobial lasso peptide arcumycin.</p>


2021 ◽  
Author(s):  
Lydia Stariha ◽  
Dewey G. McCafferty

<p>Lasso peptides are a structurally diverse superfamily of</p><p>conformationally-constrained peptide natural products, of which a</p><p>subset exhibits broad antimicrobial activity. Although advances in</p><p>bioinformatics have increased our knowledge of strains harboring</p><p>the biosynthetic machinery for lasso peptide production, relating</p><p>peptide sequence to bioactivity remains a continuous challenge.</p><p>Towards this end, a structure-driven genome mining investigation</p><p>of Actinobacteria-produced antimicrobial lasso peptides was</p><p>performed to correlate predicted primary structure with antibiotic</p><p>activity. Bioinformatic evaluation revealed eight putative novel</p><p>class I lasso peptide sequences. This subset is predicted to</p><p>possess antibiotic activity as characterized members of this class</p><p>have both broad spectrum and potent activity against Gram positive</p><p>strains. Fermentation of one of these hits, Streptomyces</p><p>NRRL F-5639, resulted in the production of a novel class I lasso</p><p>peptide, arcumycin, named for the Latin word for bow or arch,</p><p>arcum. Arcumycin exhibited antibiotic activity against Gram positive</p><p>bacteria including <i>Bacillus subtilis</i> (4 μg/mL),</p><p><i>Staphylococcus aureus </i>(8 μg/mL), and <i>Micrococcus luteus</i> (8</p><p>μg/mL). Arcumycin treatment of <i>B. subtilis</i> liaI-β-gal promoter</p><p>fusion reporter strain resulted in upregulation of the system liaRS</p><p>by the promoter liaI, indicating arcumycin interferes with lipid II</p><p>biosynthesis. Cumulatively, the results illustrate the relationship</p><p>between phylogenetically related lasso peptides and their</p><p>bioactivity as validated through the isolation, structural</p><p>determination, and evaluation of bioactivity of the novel class I</p><p>antimicrobial lasso peptide arcumycin.</p>


2016 ◽  
Vol 83 ◽  
pp. 548-558 ◽  
Author(s):  
Debasis Mandal ◽  
Sandeep Kumar Dash ◽  
Balaram Das ◽  
Sourav Chattopadhyay ◽  
Totan Ghosh ◽  
...  

Microbiology ◽  
1986 ◽  
Vol 132 (6) ◽  
pp. 1591-1597
Author(s):  
G. L. F. Smith ◽  
C. G. Cumming ◽  
P. W. Ross

2010 ◽  
Vol 192 (15) ◽  
pp. 4078-4079 ◽  
Author(s):  
Kathryne G. Byrne-Bailey ◽  
Kelly C. Wrighton ◽  
Ryan A. Melnyk ◽  
Peter Agbo ◽  
Terry C. Hazen ◽  
...  

ABSTRACT “Thermincola potens” strain JR is one of the first Gram-positive dissimilatory metal-reducing bacteria (DMRB) for which there is a complete genome sequence. Consistent with the physiology of this organism, preliminary annotation revealed an abundance of multiheme c-type cytochromes that are putatively associated with the periplasm and cell surface in a Gram-positive bacterium. Here we report the complete genome sequence of strain JR.


2006 ◽  
Vol 74 (7) ◽  
pp. 4200-4213 ◽  
Author(s):  
Shizhen Zhang ◽  
Nicole M. Green ◽  
Izabela Sitkiewicz ◽  
Rance B. LeFebvre ◽  
James M. Musser

ABSTRACT Group A Streptococcus (GAS) is a gram-positive human bacterial pathogen that causes infections ranging in severity from pharyngitis to life-threatening invasive disease, such as necrotizing fasciitis. Serotype M28 strains are consistently isolated from invasive infections, particularly puerperal sepsis, a severe infection that occurs during or after childbirth. We recently sequenced the genome of a serotype M28 GAS strain and discovered a novel 37.4-kb foreign genetic element designated region of difference 2 (RD2). RD2 is similar in gene content and organization to genomic islands found in group B streptococci (GBS), the major cause of neonatal infections. RD2 encodes seven proteins with conventional gram-positive secretion signal sequences, six of which have not been characterized. Herein, we report that one of these six proteins (M28_Spy1325; Spy1325) is a member of the antigen I/II family of cell surface-anchored molecules produced by oral streptococci. PCR and DNA sequence analysis found that Spy1325 is very well conserved in GAS strains of distinct M protein serotypes. As assessed by real-time TaqMan quantitative PCR, the Spy1325 gene was expressed in vitro, and Spy1325 protein was present in culture supernatants and on the GAS cell surface. Western immunoblotting and enzyme-linked immunosorbent assays indicated that Spy1325 was produced by GAS in infected mice and humans. Importantly, the immunization of mice with recombinant Spy1325 fragments conferred protection against GAS-mediated mortality. Similar to other antigen I/II proteins, recombinant Spy1325 bound purified human salivary agglutinin glycoprotein. Spy1325 may represent a shared virulence factor among GAS, GBS, and oral streptococci.


2019 ◽  
Author(s):  
Carolin M Kobras ◽  
Hannah Piepenbreier ◽  
Jennifer Emenegger ◽  
Andre Sim ◽  
Georg Fritz ◽  
...  

ABSTRACTResistance against cell wall-active antimicrobial peptides in bacteria is often mediated by transporters. In low GC-content Gram-positive bacteria, a wide-spread type of such transporters are the BceAB-like systems, which frequently provide a high level of resistance against peptide antibiotics that target intermediates of the lipid II cycle of cell wall synthesis. How a transporter can offer protection from drugs that are active on the cell surface, however, has presented researchers with a conundrum. Multiple theories have been discussed, ranging from removal of the peptides from the membrane, internalisation of the drug for degradation, to removal of the cellular target rather than the drug itself. To resolve this much-debated question, we here investigated the mode of action of the transporter BceAB of Bacillus subtilis. We show that it does not inactivate or import its substrate antibiotic bacitracin. Moreover, we present evidence that the critical factor driving transport activity is not the drug itself, but instead the concentration of drug-target complexes in the cell. Our results, together with previously reported findings, lead us to propose that BceAB-type transporters act by transiently freeing lipid II cycle intermediates from the inhibitory grip of antimicrobial peptides, and thus provide resistance through target protection of cell wall synthesis. Target protection has so far only been reported for resistance against antibiotics with intracellular targets, such as the ribosome. However, this mechanism offers a plausible explanation for the use of transporters as resistance determinants against cell wall-active antibiotics in Gram-positive bacteria where cell wall synthesis lacks the additional protection of an outer membrane.


2019 ◽  
Author(s):  
N.L. Costa ◽  
B. Hermann ◽  
V. Fourmond ◽  
M. Faustino ◽  
M. Teixeira ◽  
...  

AbstractExtracellular electron transfer is the key process underpinning the development of bioelectrochemical systems for the production of energy or added-value compounds. Thermincola potens JR is a promising Gram-positive bacterium to be used in these systems because it is thermophilic. In this paper we describe the structural and functional properties of the nonaheme cytochrome OcwA, which is the terminal reductase of this organism. The structure of OcwA, determined at 2.2Å resolution shows that the overall-fold and organization of the hemes are not related to other metal reductases and instead are similar to that of multiheme cytochromes involved in the biogeochemical cycles of nitrogen and sulfur. We show that, in addition to solid electron acceptors, OcwA can also reduce soluble electron shuttles and oxyanions. These data reveal that OcwA can take the role of a respiratory ‘swiss-army knife’ allowing this organism to grow in environments with rapidly changing availability of terminal electron acceptors without the need for transcriptional regulation and protein synthesis.ImportanceThermophilic Gram-positive organisms were recently shown to be a promising class of organisms to be used in bioelectrochemical systems for the production of electrical energy. These organisms present a thick peptidoglycan layer that was thought to preclude them to perform extracellular electron transfer (i.e. exchange catabolic electrons with solid electron acceptors outside of the cell). In this manuscript we describe the structure and functional mechanisms of the multiheme cytochrome OcwA, the terminal reductase of the Gram-positive bacterium Thermincola potens JR found at the cell surface of this organism. The results presented here show that this protein is unrelated with terminal reductases found at the cell surface of other electroactive organisms. Instead, OcwA is similar to terminal reductases of soluble electron acceptors. Our data reveals that terminal oxidoreductases of soluble and insoluble substrates are evolutionarily related, providing novel insights into the evolutionary pathway of multiheme cytochromes.


2021 ◽  
Author(s):  
Trinh Lam ◽  
Courtney K. Ellison ◽  
Ankur B. Dalia ◽  
David T. Eddington ◽  
Donald A. Morrison

SUMMARYThe competence pili of transformable Gram-positive species form a subset of the diverse and widespread class of extracellular filamentous organelles known as type IV pili (T4P). In Gram-negative bacteria, T4P act through dynamic cycles of extension and retraction to carry out diverse activities including attachment, motility, protein secretion, and DNA uptake. It remains unclear whether T4P in Gram-positive species exhibit this same dynamic activity, and their mechanism of action for DNA uptake remains unclear. They are hypothesized to either (1) passively form transient cavities in the cell wall to facilitate DNA passage, (2) act as static adhesins to enrich DNA near the cell surface for subsequent uptake by membrane-embedded transporters, or (3) play an active role in translocating bound DNA via their dynamic activity. Here, using a recently described pilus labeling approach, we demonstrate that pneumococcal competence pili are highly dynamic structures that rapidly extend and retract from the cell surface. By labeling ComGC with bulky adducts, we further demonstrate that pilus retraction is essential for natural transformation. Together, our results indicate that Gram-positive type IV competence pili are dynamic and retractile structures that play an active role in DNA uptake.Short summaryCompetent pneumococci kill non-competent cells on contact. Retractable DNA-binding fibers in the class of type IV pili may provide a key tool for retrieving DNA segments from cell wreckage for internalization and recombination.


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