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Streptococcus pneumoniae detects and responds to foreign bacterial peptide fragments in its environment.

Hathaway LJ, Bättig P, Reber S, Rotzetter JU, Aebi S, Hauser C, Heller M, Kadioglu A, Mühlemann K - Open Biol (2014)

Bottom Line: AliB-like ORF 1 binds specifically peptide SETTFGRDFN, matching 50S ribosomal subunit protein L4 of Enterobacteriaceae, and facilitates upregulation of competence for genetic transformation.We found that AliB-like ORF 2 mediates the early phase of nasopharyngeal colonization in vivo.These findings reveal a completely new concept of pneumococcal interspecies communication which may have implications for communication between other bacterial species and for future interventional therapeutics.

View Article: PubMed Central - PubMed

Affiliation: Institute for Infectious Diseases, University of Bern, Bern, Switzerland.

ABSTRACT
Streptococcus pneumoniae is an important cause of bacterial meningitis and pneumonia but usually colonizes the human nasopharynx harmlessly. As this niche is simultaneously populated by other bacterial species, we looked for a role and pathway of communication between pneumococci and other species. This paper shows that two proteins of non-encapsulated S. pneumoniae, AliB-like ORF 1 and ORF 2, bind specifically to peptides matching other species resulting in changes in the pneumococci. AliB-like ORF 1 binds specifically peptide SETTFGRDFN, matching 50S ribosomal subunit protein L4 of Enterobacteriaceae, and facilitates upregulation of competence for genetic transformation. AliB-like ORF 2 binds specifically peptides containing sequence FPPQS, matching proteins of Prevotella species common in healthy human nasopharyngeal microbiota. We found that AliB-like ORF 2 mediates the early phase of nasopharyngeal colonization in vivo. The ability of S. pneumoniae to bind and respond to peptides of other bacterial species occupying the same host niche may play a key role in adaptation to its environment and in interspecies communication. These findings reveal a completely new concept of pneumococcal interspecies communication which may have implications for communication between other bacterial species and for future interventional therapeutics.

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Binding of recombinant AliB-like ORFs to their ligands. Binding of recombinant AliB-like ORF 1 (a–d) and AliB-like ORF 2 (e–k) to synthetic peptides was determined by measuring changes in intrinsic protein fluorescence using tryptophan fluorescence. A drop in fluorescence indicates binding. Peptide sequences are indicated above the arrows marking the moment of their addition to the protein.
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RSOB130224F2: Binding of recombinant AliB-like ORFs to their ligands. Binding of recombinant AliB-like ORF 1 (a–d) and AliB-like ORF 2 (e–k) to synthetic peptides was determined by measuring changes in intrinsic protein fluorescence using tryptophan fluorescence. A drop in fluorescence indicates binding. Peptide sequences are indicated above the arrows marking the moment of their addition to the protein.

Mentions: Tryptophan fluorescence binding assays confirmed that the ligand of AliB-like ORF 1 is SETTFGRDFN (figure 2a). (Testing of a longer peptide containing the AliB-like ORF 1 ligand sequence was prevented by its insolubility.) Binding was specific as a peptide with one amino acid difference (SETTFGREFN), the equivalent sequence in Haemophilus influenzae, a human pathogen which colonizes the nasopharynx, did not bind (figure 2b). Also, AliB-like ORF 2 ligand FPPQSV (figure 2c) and the putative ligand for real-AliB (LRRASLG) (figure 2d) did not bind AliB-like ORF 1 protein. The tryptophan fluorescence assay also confirmed that the ligand of AliB-like ORF 2 is FPPQSV (figure 2e) with a positive, but weaker, signal with FPPQS (figure 2f). AliB-like ORF 2 was more promiscuous than AliB-like ORF 1 as AliB-like ORF 2 protein also bound FPPQSI (P. tannerae, putative ABC transporter) (figure 2g) and FPPQNV (human Deltex 1) (figure 2h) though it did not bind the completely unrelated peptides of the AliB-like ORF 1 ligand (figure 2i) or the ligand for real-AliB (LRRASLG) (figure 2j). Binding of AliB-like ORF 2 protein was also observed with peptide IEAFPPQSVKGK (figure 2k) representing AliB-like ORF 2 ligand (underlined) flanked by three amino acids either side that are found adjacent to the ligand sequence in P. salivae GTPase EngA.Figure 2.


Streptococcus pneumoniae detects and responds to foreign bacterial peptide fragments in its environment.

Hathaway LJ, Bättig P, Reber S, Rotzetter JU, Aebi S, Hauser C, Heller M, Kadioglu A, Mühlemann K - Open Biol (2014)

Binding of recombinant AliB-like ORFs to their ligands. Binding of recombinant AliB-like ORF 1 (a–d) and AliB-like ORF 2 (e–k) to synthetic peptides was determined by measuring changes in intrinsic protein fluorescence using tryptophan fluorescence. A drop in fluorescence indicates binding. Peptide sequences are indicated above the arrows marking the moment of their addition to the protein.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4043112&req=5

RSOB130224F2: Binding of recombinant AliB-like ORFs to their ligands. Binding of recombinant AliB-like ORF 1 (a–d) and AliB-like ORF 2 (e–k) to synthetic peptides was determined by measuring changes in intrinsic protein fluorescence using tryptophan fluorescence. A drop in fluorescence indicates binding. Peptide sequences are indicated above the arrows marking the moment of their addition to the protein.
Mentions: Tryptophan fluorescence binding assays confirmed that the ligand of AliB-like ORF 1 is SETTFGRDFN (figure 2a). (Testing of a longer peptide containing the AliB-like ORF 1 ligand sequence was prevented by its insolubility.) Binding was specific as a peptide with one amino acid difference (SETTFGREFN), the equivalent sequence in Haemophilus influenzae, a human pathogen which colonizes the nasopharynx, did not bind (figure 2b). Also, AliB-like ORF 2 ligand FPPQSV (figure 2c) and the putative ligand for real-AliB (LRRASLG) (figure 2d) did not bind AliB-like ORF 1 protein. The tryptophan fluorescence assay also confirmed that the ligand of AliB-like ORF 2 is FPPQSV (figure 2e) with a positive, but weaker, signal with FPPQS (figure 2f). AliB-like ORF 2 was more promiscuous than AliB-like ORF 1 as AliB-like ORF 2 protein also bound FPPQSI (P. tannerae, putative ABC transporter) (figure 2g) and FPPQNV (human Deltex 1) (figure 2h) though it did not bind the completely unrelated peptides of the AliB-like ORF 1 ligand (figure 2i) or the ligand for real-AliB (LRRASLG) (figure 2j). Binding of AliB-like ORF 2 protein was also observed with peptide IEAFPPQSVKGK (figure 2k) representing AliB-like ORF 2 ligand (underlined) flanked by three amino acids either side that are found adjacent to the ligand sequence in P. salivae GTPase EngA.Figure 2.

Bottom Line: AliB-like ORF 1 binds specifically peptide SETTFGRDFN, matching 50S ribosomal subunit protein L4 of Enterobacteriaceae, and facilitates upregulation of competence for genetic transformation.We found that AliB-like ORF 2 mediates the early phase of nasopharyngeal colonization in vivo.These findings reveal a completely new concept of pneumococcal interspecies communication which may have implications for communication between other bacterial species and for future interventional therapeutics.

View Article: PubMed Central - PubMed

Affiliation: Institute for Infectious Diseases, University of Bern, Bern, Switzerland.

ABSTRACT
Streptococcus pneumoniae is an important cause of bacterial meningitis and pneumonia but usually colonizes the human nasopharynx harmlessly. As this niche is simultaneously populated by other bacterial species, we looked for a role and pathway of communication between pneumococci and other species. This paper shows that two proteins of non-encapsulated S. pneumoniae, AliB-like ORF 1 and ORF 2, bind specifically to peptides matching other species resulting in changes in the pneumococci. AliB-like ORF 1 binds specifically peptide SETTFGRDFN, matching 50S ribosomal subunit protein L4 of Enterobacteriaceae, and facilitates upregulation of competence for genetic transformation. AliB-like ORF 2 binds specifically peptides containing sequence FPPQS, matching proteins of Prevotella species common in healthy human nasopharyngeal microbiota. We found that AliB-like ORF 2 mediates the early phase of nasopharyngeal colonization in vivo. The ability of S. pneumoniae to bind and respond to peptides of other bacterial species occupying the same host niche may play a key role in adaptation to its environment and in interspecies communication. These findings reveal a completely new concept of pneumococcal interspecies communication which may have implications for communication between other bacterial species and for future interventional therapeutics.

Show MeSH
Related in: MedlinePlus