scholarly journals The Streptococcus pyogenes Shr protein captures human hemoglobin using two structurally unique binding domains

2018 ◽  
Vol 293 (47) ◽  
pp. 18365-18377 ◽  
Author(s):  
Ramsay Macdonald ◽  
Duilio Cascio ◽  
Michael J. Collazo ◽  
Martin Phillips ◽  
Robert T. Clubb
Keyword(s):  
Streptococcus Pyogenes ◽  
The Body ◽  
Human Hemoglobin ◽  
Heme Binding ◽  
Human Pathogen ◽  
Nmr Studies ◽  
Binding Domains ◽  
Biochemical Studies ◽  
Important Virulence Factor ◽  
Linker Domain

In order to proliferate and mount an infection, many bacterial pathogens need to acquire iron from their host. The most abundant iron source in the body is the oxygen transporter hemoglobin (Hb). Streptococcus pyogenes, a potentially lethal human pathogen, uses the Shr protein to capture Hb on the cell surface. Shr is an important virulence factor, yet the mechanism by which it captures Hb and acquires its heme is not well-understood. Here, we show using NMR and biochemical methods that Shr binds Hb using two related modules that were previously defined as domains of unknown function (DUF1533). These hemoglobin-interacting domains (HIDs), called HID1 and HID2, are autonomously folded and independently bind Hb. The 1.5 Å resolution crystal structure of HID2 revealed that it is a structurally unique Hb-binding domain. Mutagenesis studies revealed a conserved tyrosine in both HIDs that is essential for Hb binding. Our biochemical studies indicate that HID2 binds Hb with higher affinity than HID1 and that the Hb tetramer is engaged by two Shr receptors. NMR studies reveal the presence of a third autonomously folded domain between HID2 and a heme-binding NEAT1 domain, suggesting that this linker domain may position NEAT1 near Hb for heme capture.

scholarly journals Transcriptomic Analysis ofStreptococcus pyogenesColonizing the Vaginal Mucosa IdentifieshupY, an MtsR-Regulated Adhesin Involved in Heme Utilization

mBio ◽  
2019 ◽  
Vol 10 (3) ◽  
Author(s):  
Laura C. C. Cook ◽  
Nilanjana Chatterjee ◽  
Yan Li ◽  
Jorge Andrade ◽  
Michael J. Federle ◽  
...  
Keyword(s):  
Streptococcus Pyogenes ◽  
Streptococcus Agalactiae ◽  
Iron Homeostasis ◽  
Vaginal Mucosa ◽  
Heme Binding ◽  
Human Pathogen ◽  
Intracellular Iron ◽  
Essential Information ◽  
Content Type ◽  
Vaginal Colonization

ABSTRACTStreptococcus pyogenes(group A streptococcus [GAS]) is a serious human pathogen with the ability to colonize mucosal surfaces such as the nasopharynx and vaginal tract, often leading to infections such as pharyngitis and vulvovaginitis. We present genome-wide transcriptome sequencing (RNASeq) data showing the transcriptomic changes GAS undergoes during vaginal colonization. These data reveal that the regulon controlled by MtsR, a master metal regulator, is activated during vaginal colonization. This regulon includes two genes highly expressed during vaginal colonization,hupYZ. Here we show that HupY binds hemein vitro, affects intracellular concentrations of iron, and is essential for proper growth of GAS using hemoglobin or serum as the sole iron source. HupY is also important for murine vaginal colonization of both GAS and the related vaginal colonizer and pathogenStreptococcus agalactiae(group B streptococcus [GBS]). These data provide essential information on the link between metal regulation and mucosal colonization in both GAS and GBS.IMPORTANCEColonization of the host requires the ability to adapt to an environment that is often low in essential nutrients such as iron. Here we present data showing that the transcriptome of the important human pathogenStreptococcus pyogenesshows extensive remodeling duringin vivogrowth, resulting in, among many other differentially expressed genes and pathways, a significant increase in genes involved in acquiring iron from host heme. Data show that HupY, previously characterized as an adhesin in bothS. pyogenesand the related pathogenStreptococcus agalactiae, binds heme and affects intracellular iron concentrations. HupY, a protein with no known heme binding domains, represents a novel heme binding protein playing an important role in bacterial iron homeostasis as well as vaginal colonization.

Prisoners of XYY Constitution: Biochemical Studies

1972 ◽  
Vol 121 (563) ◽  
pp. 365-368 ◽  
Author(s):  
A. W. Griffiths ◽  
V. Marks ◽  
D. Fry ◽  
G. Morley ◽  
Gillian Lewis
Keyword(s):  
General Population ◽  
Sex Hormones ◽  
Psychiatric Hospitals ◽  
The Body ◽  
Plasma Testosterone ◽  
Testosterone Levels ◽  
Maximum Security ◽  
Significant Difference ◽  
Biochemical Studies ◽  
Psychopathic Disorder

The XYY constitution has achieved some measure of clinical definition, having been found in association with tallness, asocial personality, dilution of intelligence (Griffiths, 1971) and a tendency to psychopathic disorder (Griffiths, Richards, Zaremba, Abramowicz and Stewart, 1970). In addition, neurological, endocrinological, skeletal and other abnormalities have been reviewed (Griffiths, 1971), and the condition, like mongolism, has come to be regarded as affecting many systems of the body to a greater or lesser extent. Biochemical investigations, hitherto largely concerned with sex hormones, especially testosterone, have in general revealed no significant difference from matched controls. Some authors have, however, reported increased plasma testosterone levels both in 46 XY and 47 XYY patients of maximum security hospitals as compared to patients in other psychiatric hospitals and to the general population (Ismail, Harkness, Kirkham, Loraine, Whatmore and Brittain, 1968; Rudd, Galal and Casey, 1968; Price and Van de Molen, 1970). The pre-eminent desirability of rigorously selected controls has been remarked on in these investigations.

scholarly journals The Streptococcal Protease SpeB Antagonizes the Biofilms of the Human Pathogen Staphylococcus aureus USA300 through Cleavage of the Staphylococcal SdrC Protein

2020 ◽  
Vol 202 (11) ◽  
Author(s):  
Katelyn E. Carothers ◽  
Zhong Liang ◽  
Jeffrey Mayfield ◽  
Deborah L. Donahue ◽  
Mijoon Lee ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Proteolytic Activity ◽  
Streptococcus Pyogenes ◽  
Human Pathogen ◽  
Content Type ◽  
Functional Studies ◽  
Human Proteins ◽  
Group A ◽  
Biofilm Disruption

ABSTRACT Streptococcus pyogenes, or group A Streptococcus (GAS), is both a pathogen and an asymptomatic colonizer of human hosts and produces a large number of surface-expressed and secreted factors that contribute to a variety of infection outcomes. The GAS-secreted cysteine protease SpeB has been well studied for its effects on the human host; however, despite its broad proteolytic activity, studies on how this factor is utilized in polymicrobial environments are lacking. Here, we utilized various forms of SpeB protease to evaluate its antimicrobial and antibiofilm properties against the clinically important human colonizer Staphylococcus aureus, which occupies niches similar to those of GAS. For our investigation, we used a skin-tropic GAS strain, AP53CovS+, and its isogenic ΔspeB mutant to compare the production and activity of native SpeB protease. We also generated active and inactive forms of recombinant purified SpeB for functional studies. We demonstrate that SpeB exhibits potent biofilm disruption activity at multiple stages of S. aureus biofilm formation. We hypothesized that the surface-expressed adhesin SdrC in S. aureus was cleaved by SpeB, which contributed to the observed biofilm disruption. Indeed, we found that SpeB cleaved recombinant SdrC in vitro and in the context of the full S. aureus biofilm. Our results suggest an understudied role for the broadly proteolytic SpeB as an important factor for GAS colonization and competition with other microorganisms in its niche. IMPORTANCE Streptococcus pyogenes (GAS) causes a range of diseases in humans, ranging from mild to severe, and produces many virulence factors in order to be a successful pathogen. One factor produced by many GAS strains is the protease SpeB, which has been studied for its ability to cleave and degrade human proteins, an important factor in GAS pathogenesis. An understudied aspect of SpeB is the manner in which its broad proteolytic activity affects other microorganisms that co-occupy niches similar to that of GAS. The significance of the research reported herein is the demonstration that SpeB can degrade the biofilms of the human pathogen Staphylococcus aureus, which has important implications for how SpeB may be utilized by GAS to successfully compete in a polymicrobial environment.

scholarly journals The Arginine Deiminase Pathway Impacts Antibiotic Tolerance during Biofilm-Mediated Streptococcus pyogenes Infections

mBio ◽  
2020 ◽  
Vol 11 (4) ◽  
Author(s):  
Jeffrey A. Freiberg ◽  
Yoann Le Breton ◽  
Janette M. Harro ◽  
Devon L. Allison ◽  
Kevin S. McIver ◽  
...  
Keyword(s):  
Treatment Failure ◽  
Antibiotic Treatment ◽  
Streptococcus Pyogenes ◽  
Bacterial Infections ◽  
Bacterial Species ◽  
Arginine Deiminase ◽  
Antibiotic Tolerance ◽  
Human Pathogen ◽  
Biofilm Growth ◽  
Content Type

ABSTRACT Bacterial biofilms are responsible for a variety of serious human infections and are notoriously difficult to treat due to their recalcitrance to antibiotics. Further work is necessary to elicit a full understanding of the mechanism of this antibiotic tolerance. The arginine deiminase (ADI) pathway is responsible for bacterial pH maintenance and is highly expressed during biofilm growth in multiple bacterial species. Using the group A Streptococcus (GAS) as a model human pathogen, the ADI pathway was demonstrated to contribute to biofilm growth. The inability of antibiotics to reduce GAS populations when in a biofilm was demonstrated by in vitro studies and a novel animal model of nasopharyngeal infection. However, disruption of the ADI pathway returned GAS biofilms to planktonic levels of antibiotic sensitivity, suggesting the ADI pathway is influential in biofilm-related antibiotic treatment failure and provides a new strategic target for the treatment of biofilm infections in GAS and potentially numerous other bacterial species. IMPORTANCE Biofilm-mediated bacterial infections are a major threat to human health because of their recalcitrance to antibiotic treatment. Through the study of Streptococcus pyogenes, a significant human pathogen that is known to form antibiotic-tolerant biofilms, we demonstrated the role that a bacterial pathway known for responding to acid stress plays in biofilm growth and antibiotic tolerance. This not only provides some insight into antibiotic treatment failure in S. pyogenes infections but also, given the widespread nature of this pathway, provides a potentially broad target for antibiofilm therapies. This discovery has the potential to impact the treatment of many different types of recalcitrant biofilm infections.

scholarly journals Iron is a ligand of SecA-like metal-binding domains in vivo

2020 ◽  
Vol 295 (21) ◽  
pp. 7516-7528
Author(s):  
Tamar Cranford-Smith ◽  
Mohammed Jamshad ◽  
Mark Jeeves ◽  
Rachael A. Chandler ◽  
Jack Yule ◽  
...  
Keyword(s):  
Sodium Azide ◽  
Metal Binding ◽  
Cytoplasmic Membrane ◽  
E Coli ◽  
Binding Domains ◽  
Equilibrium Binding ◽  
Plausible Model ◽  
Metal Binding Domain ◽  
Linker Domain

The ATPase SecA is an essential component of the bacterial Sec machinery, which transports proteins across the cytoplasmic membrane. Most SecA proteins contain a long C-terminal tail (CTT). In Escherichia coli, the CTT contains a structurally flexible linker domain and a small metal-binding domain (MBD). The MBD coordinates zinc via a conserved cysteine-containing motif and binds to SecB and ribosomes. In this study, we screened a high-density transposon library for mutants that affect the susceptibility of E. coli to sodium azide, which inhibits SecA-mediated translocation. Results from sequencing this library suggested that mutations removing the CTT make E. coli less susceptible to sodium azide at subinhibitory concentrations. Copurification experiments suggested that the MBD binds to iron and that azide disrupts iron binding. Azide also disrupted binding of SecA to membranes. Two other E. coli proteins that contain SecA-like MBDs, YecA and YchJ, also copurified with iron, and NMR spectroscopy experiments indicated that YecA binds iron via its MBD. Competition experiments and equilibrium binding measurements indicated that the SecA MBD binds preferentially to iron and that a conserved serine is required for this specificity. Finally, structural modeling suggested a plausible model for the octahedral coordination of iron. Taken together, our results suggest that SecA-like MBDs likely bind to iron in vivo.

scholarly journals A Novel Sortase, SrtC2, from Streptococcus pyogenes Anchors a Surface Protein Containing a QVPTGV Motif to the Cell Wall

2004 ◽  
Vol 186 (17) ◽  
pp. 5865-5875 ◽  
Author(s):  
Timothy C. Barnett ◽  
Aman R. Patel ◽  
June R. Scott
Keyword(s):  
Cell Wall ◽  
Streptococcus Pyogenes ◽  
Group A Streptococcus ◽  
Surface Protein ◽  
Surface Proteins ◽  
Human Pathogen ◽  
Hydrophobic Region ◽  
C Terminus ◽  
Group A ◽  
Covalently Linked

ABSTRACT The important human pathogen Streptococcus pyogenes (group A streptococcus GAS), requires several surface proteins to interact with its human host. Many of these are covalently linked by a sortase enzyme to the cell wall via a C-terminal LPXTG motif. This motif is followed by a hydrophobic region and charged C terminus, which are thought to retard the protein in the cell membrane to facilitate recognition by the membrane-localized sortase. Previously, we identified two sortase enzymes in GAS. SrtA is found in all GAS strains and anchors most proteins containing LPXTG, while SrtB is present only in some strains and anchors a subset of LPXTG-containing proteins. We now report the presence of a third sortase in most strains of GAS, SrtC. We show that SrtC mediates attachment of a protein with a QVPTGV motif preceding a hydrophobic region and charged tail. We also demonstrate that the QVPTGV sequence is a substrate for anchoring of this protein by SrtC. Furthermore, replacing this motif with LPSTGE, found in the SrtA-anchored M protein of GAS, leads to SrtA-dependent secretion of the protein but does not lead to its anchoring by SrtA. We conclude that srtC encodes a novel sortase that anchors a protein containing a QVPTGV motif to the surface of GAS.

scholarly journals The Cell Wall of the Human Pathogen Candida glabrata: Differential Incorporation of Novel Adhesin-Like Wall Proteins

2008 ◽  
Vol 7 (11) ◽  
pp. 1951-1964 ◽  
Author(s):  
Piet W. J. de Groot ◽  
Eefje A. Kraneveld ◽  
Qing Yuan Yin ◽  
Henk L. Dekker ◽  
Uwe Groß ◽  
...  
Keyword(s):  
Cell Wall ◽  
Candida Glabrata ◽  
Fungal Infections ◽  
Cell Surface Hydrophobicity ◽  
Spectrometric Analysis ◽  
Human Pathogen ◽  
Microscopy Imaging ◽  
Glucose Ratio ◽  
Biochemical Studies ◽  
Gpi Proteins

ABSTRACT The cell wall of the human pathogen Candida glabrata governs initial host-pathogen interactions that underlie the establishment of fungal infections. With the aim of identifying species-specific features that may directly relate to its virulence, we have investigated the cell wall of C. glabrata using a multidisciplinary approach that combines microscopy imaging, biochemical studies, bioinformatics, and tandem mass spectrometry. Electron microscopy revealed a bilayered wall structure in which the outer layer is packed with mannoproteins. Biochemical studies showed that C. glabrata walls incorporate 50% more protein than Saccharomyces cerevisiae walls and, consistent with this, have a higher mannose/glucose ratio. Evidence is presented that C. glabrata walls contain glycosylphosphatidylinositol (GPI) proteins, covalently bound to the wall 1,6-β-glucan, as well as proteins linked through a mild-alkali-sensitive linkage to 1,3-β-glucan. A comprehensive genome-wide in silico inspection showed that in comparison to other fungi, C. glabrata contains an exceptionally large number, 67, of genes encoding adhesin-like GPI proteins. Phylogenetically these adhesin-like proteins form different clusters, one of which is the lectin-like EPA family. Mass spectrometric analysis identified 23 cell wall proteins, including 4 novel adhesin-like proteins, Awp1/2/3/4, and Epa6, which is involved in adherence to human epithelia and biofilm formation. Importantly, the presence of adhesin-like proteins in the wall depended on the growth stage and on the genetic background used, and this was reflected in alterations in adhesion capacity and cell surface hydrophobicity. We propose that the large repertoire of adhesin(-like) genes of C. glabrata contributes to its adaptability and virulence.

scholarly journals One More Disguise in the Stealth Behavior of Streptococcus pyogenes

mBio ◽  
2016 ◽  
Vol 7 (3) ◽  
Author(s):  
Vincent A. Fischetti ◽  
James B. Dale
Keyword(s):  
Hyaluronic Acid ◽  
Streptococcus Pyogenes ◽  
Treated Patient ◽  
Vantage Point ◽  
The Body ◽  
Eukaryotic Cells ◽  
Animal Kingdom ◽  
Human Joints ◽  
Hyaluronic Acid Capsule ◽  
Acid Lining

ABSTRACT The ability to hide in the animal kingdom is essential for survival; the same is true for bacteria . Streptococcus pyogenes is considered one of the more successful stealth bacteria in its production of a hyaluronic acid capsule that is chemically identical to the hyaluronic acid lining human joints. It has also acquired the capacity to enter eukaryotic cells to avoid the onslaught of the host’s immune defenses, as well as drugs. From this intracellular vantage point, it may remain dormant from days to weeks, only to cause disease again at a later time, perhaps causing a relapse in a drug-treated patient. We now learn that it is able to enter macrophages as well, enabling the Streptococcus to use this “Trojan horse” approach to be transported to distant sites in the body.

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