3TXA

Structural Analysis of Adhesive Tip pilin, GBS104 from Group B Streptococcus agalactiae

Summary for 3TXA

• Entry DOI: 10.2210/pdb3txa/pdb
• Related: 3TVY 3TW0
• Descriptor: Cell wall surface anchor family protein, MAGNESIUM ION, CADMIUM ION, ... (5 entities in total)
• Functional Keywords: vwfa fold, igg-like fold, ancillary pilin, gram-positive bacterial cell surface, cell adhesion
• Biological source: Streptococcus agalactiae serogroup V
• Total number of polymer chains: 1
• Total formula weight: 77176.87

Authors

Krishnan, V.,Narayana, S.V.L. (deposition date: 2011-09-23, release date: 2013-03-27, Last modification date: 2024-10-30)

Primary citation

Krishnan, V.,Dwivedi, P.,Kim, B.J.,Samal, A.,Macon, K.,Ma, X.,Mishra, A.,Doran, K.S.,Ton-That, H.,Narayana, S.V.
Structure of Streptococcus agalactiae tip pilin GBS104: a model for GBS pili assembly and host interactions.
Acta Crystallogr.,Sect.D, 69:1073-1089, 2013

PubMed Abstract: The crystal structure of a 75 kDa central fragment of GBS104, a tip pilin from the 2063V/R strain of Streptococcus agalactiae (group B streptococcus; GBS), is reported. In addition, a homology model of the remaining two domains of GBS104 was built and a model of full-length GBS104 was generated by combining the homology model (the N1 and N4 domains) and the crystal structure of the 75 kDa fragment (the N2 and N3 domains). This rod-shaped GBS104 model is constructed of three IgG-like domains (the N1, N2 and N4 domains) and one vWFA-like domain (the N3 domain). The N1 and N2 domains of GBS104 are assembled with distinct and remote segments contributed by the N- and C-termini. The metal-binding site in the N3 domain of GBS104 is in the closed/low-affinity conformation. Interestingly, this domain hosts two long arms that project away from the metal-binding site. Using site-directed mutagenesis, two cysteine residues that lock the N3 domain of GBS104 into the open/high-affinity conformation were introduced. Both wild-type and disulfide-locked recombinant proteins were tested for binding to extracellular matrix proteins such as collagen, fibronectin, fibrinogen and laminin, and an increase in fibronectin binding affinity was identified for the disulfide-locked N3 domain, suggesting that induced conformational changes may play a possible role in receptor binding.

PubMed: 23695252
DOI: 10.1107/S0907444913004642

Experimental method

X-RAY DIFFRACTION (2.619 Å)