2i2h
From Proteopedia
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| - | + | {{STRUCTURE_2i2h| PDB=2i2h | SCENE= }} | |
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'''NMR structure of TPC3 in TFE''' | '''NMR structure of TPC3 in TFE''' | ||
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==About this Structure== | ==About this Structure== | ||
| - | + | Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2I2H OCA]. | |
==Reference== | ==Reference== | ||
Structure-activity analysis of quorum-sensing signaling peptides from Streptococcus mutans., Syvitski RT, Tian XL, Sampara K, Salman A, Lee SF, Jakeman DL, Li YH, J Bacteriol. 2007 Feb;189(4):1441-50. Epub 2006 Aug 25. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/16936029 16936029] | Structure-activity analysis of quorum-sensing signaling peptides from Streptococcus mutans., Syvitski RT, Tian XL, Sampara K, Salman A, Lee SF, Jakeman DL, Li YH, J Bacteriol. 2007 Feb;189(4):1441-50. Epub 2006 Aug 25. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/16936029 16936029] | ||
| - | [[Category: Protein complex]] | ||
[[Category: Jakeman, D L.]] | [[Category: Jakeman, D L.]] | ||
[[Category: Li, Y.]] | [[Category: Li, Y.]] | ||
[[Category: Syvitski, R T.]] | [[Category: Syvitski, R T.]] | ||
| - | [[Category: | + | [[Category: Helix]] |
| - | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun May 4 06:59:48 2008'' | |
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | |
Revision as of 03:59, 4 May 2008
NMR structure of TPC3 in TFE
Overview
Streptococcus mutans secretes and utilizes a 21-amino-acid signaling peptide pheromone to initiate quorum sensing for genetic competence, biofilm formation, stress responses, and bacteriocin production. In this study, we designed and synthesized a series of truncated peptides and peptides with amino acid substitutions to investigate their structure-activity relationships based on the three-dimensional structures of S. mutans wild-type signaling peptide UA159sp and C-terminally truncated peptide TPC3 from mutant JH1005 defective in genetic competence. By analyzing these peptides, we demonstrated that the signaling peptide of S. mutans has at least two functional domains. The C-terminal structural motif consisting of a sequence of polar hydrophobic charged residues is crucial for activation of the signal transduction pathway, while the core alpha-helical structure extending from residue 5 to the end of the peptide is required for receptor binding. Peptides in which three or more residues were deleted from the C terminus did not induce genetic competence but competitively inhibited quorum sensing activated by UA159sp. Disruption of the amphipathic alpha-helix by replacing the Phe-7, Phe-11, or Phe-15 residue with a hydrophilic residue resulted in a significant reduction in or complete loss of the activity of the peptide. In contrast to the C-terminally truncated peptides, these peptides with amino acid substitutions did not compete with UA159sp to activate quorum sensing, suggesting that disruption of the hydrophobic face of the alpha-helical structure results in a peptide that is not able to bind to the receptor. This study is the first study to recognize the importance of the signaling peptide C-terminal residues in streptococcal quorum sensing.
About this Structure
Full crystallographic information is available from OCA.
Reference
Structure-activity analysis of quorum-sensing signaling peptides from Streptococcus mutans., Syvitski RT, Tian XL, Sampara K, Salman A, Lee SF, Jakeman DL, Li YH, J Bacteriol. 2007 Feb;189(4):1441-50. Epub 2006 Aug 25. PMID:16936029 Page seeded by OCA on Sun May 4 06:59:48 2008
