3RGU

Structure of Fap-NRa at pH 5.0

Summary for 3RGU

• Entry DOI: 10.2210/pdb3rgu/pdb
• Related: 2KUB
• Descriptor: Fimbriae-associated protein Fap1, alpha-D-glucopyranose (3 entities in total)
• Functional Keywords: helical bundle, cell wall, peptidoglycan-anchor, adhesion, dental caries, ph, structural protein
• Biological source: Streptococcus parasanguinis
• Total number of polymer chains: 4
• Total formula weight: 58000.93

Authors

Garnett, J.A.,Matthews, S.J. (deposition date: 2011-04-09, release date: 2011-12-28, Last modification date: 2023-09-13)

Primary citation

Garnett, J.A.,Simpson, P.J.,Taylor, J.,Benjamin, S.V.,Tagliaferri, C.,Cota, E.,Chen, Y.Y.,Wu, H.,Matthews, S.
Structural insight into the role of Streptococcus parasanguinis Fap1 within oral biofilm formation.
Biochem.Biophys.Res.Commun., 417:421-426, 2012

PubMed Abstract: The fimbriae-associated protein 1 (Fap1) is a major adhesin of Streptococcus parasanguinis, a primary colonizer of the oral cavity that plays an important role in the formation of dental plaque. Fap1 is an extracellular adhesive surface fibre belonging to the serine-rich repeat protein (SRRP) family, which plays a central role in the pathogenesis of streptococci and staphylococci. The N-terminal adhesive region of Fap1 (Fap1-NR) is composed of two domains (Fap1-NR(α) and Fap1-NR(β)) and is projected away from the bacterial surface via the extensive serine-rich repeat region, for adhesion to the salivary pellicle. The adhesive properties of Fap1 are modulated through a pH switch in which a reduction in pH results in a rearrangement between the Fap1-NR(α) and Fap1-NR(β) domains, which assists in the survival of S. parasanguinis in acidic environments. We have solved the structure of Fap1-NR(α) at pH 5.0 at 3.0Ǻ resolution and reveal how subtle rearrangements of the 3-helix bundle combined with a change in electrostatic potential mediates 'opening' and activation of the adhesive region. Further, we show that pH-dependent changes are critical for biofilm formation and present an atomic model for the inter-Fap1-NR interactions which have been assigned an important role in the biofilm formation.

PubMed: 22166217
DOI: 10.1016/j.bbrc.2011.11.131

Experimental method

X-RAY DIFFRACTION (3 Å)