PDBsum entry 3txa

Cell adhesion

PDB id: 3txa

Contents

Protein chain

583 a.a.

Metals

_LI

_MG

_CD ×7

Waters ×79

PDB id:

3txa

Name:

Cell adhesion

Title:

Structural analysis of adhesive tip pilin, gbs104 from group b streptococcus agalactiae

Structure:

Cell wall surface anchor family protein. Chain: a. Fragment: n2 and n3 domains (unp residues 48-729). Synonym: gbs104, adhesive tip pilin. Engineered: yes

Source:

Streptococcus agalactiae serogroup v. Organism_taxid: 216466. Strain: 2603 v/r. Gene: sag0649. Expressed in: escherichia coli. Expression_system_taxid: 469008.

Resolution:

2.62Å R-factor: 0.208 R-free: 0.256

Authors:

V.Krishnan,S.V.L.Narayana

Key ref:

V.Krishnan et al. (2013). Structure of Streptococcus agalactiae tip pilin GBS104: a model for GBS pili assembly and host interactions. Acta Crystallogr D Biol Crystallogr, 69, 1073-1089. PubMed id: 23695252 DOI: 10.1107/S0907444913004642

Date:

23-Sep-11 Release date: 27-Mar-13

Protein chain

Q8E0S5  (Q8E0S5_STRA5) -  Cell wall surface anchor family protein, putative from Streptococcus agalactiae serotype V (strain ATCC BAA-611 / 2603 V/R)

Seq: 890 a.a.

Struc: 583 a.a.

DOI no: 10.1107/S0907444913004642

Acta Crystallogr D Biol Crystallogr 69:1073-1089 (2013)

PubMed id: 23695252

Structure of Streptococcus agalactiae tip pilin GBS104: a model for GBS pili assembly and host interactions.

V.Krishnan, P.Dwivedi, B.J.Kim, A.Samal, K.Macon, X.Ma, A.Mishra, K.S.Doran, H.Ton-That, S.V.Narayana.

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.