PDBsum entry: 2g0u

Unknown function

PDB id: 2g0u

Contents

Protein chain

92 a.a. *

* Residue conservation analysis

PDB id:

2g0u

Name:

Unknown function

Title:

Solution structure of monomeric bsal, the type iii secretion needle protein of burkholderia pseudomallei

Structure:

Type iii secretion system needle protein. Chain: a. Fragment: bsaldelta5. Engineered: yes

Source:

Burkholderia pseudomallei. Organism_taxid: 28450. Strain: e264. Expressed in: escherichia coli. Expression_system_taxid: 562

NMR struc:

20 models

Authors:

L.Zhang,Y.Wang,W.L.Picking,W.D.Picking,R.N.De Guzman

Key ref:

L.Zhang et al. (2006). Solution structure of monomeric BsaL, the type III secretion needle protein of Burkholderia pseudomallei. J Mol Biol, 359, 322-330. PubMed id: 16631790 DOI: 10.1016/j.jmb.2006.03.028

Date:

13-Feb-06 Release date: 23-May-06

Protein chain

Q63K18  (Q63K18_BURPS) -  Type III secretion system protein

Seq: 89 a.a.

Struc: 92 a.a.*

* PDB and UniProt seqs differ at 5 residue positions (black crosses)

 Gene Ontology (GO) functional annotation 

• Biological process: protein transport (2 terms)
• Biochemical function: protein transporter activity (1 term)

DOI no: 10.1016/j.jmb.2006.03.028

J Mol Biol 359:322-330 (2006)

PubMed id: 16631790

Solution structure of monomeric BsaL, the type III secretion needle protein of Burkholderia pseudomallei.

L.Zhang, Y.Wang, W.L.Picking, W.D.Picking, R.N.De Guzman.

ABSTRACT

Many gram-negative bacteria that are important human pathogens possess type III secretion systems as part of their required virulence factor repertoire. During the establishment of infection, these pathogens coordinately assemble greater than 20 different proteins into a macromolecular structure that spans the bacterial inner and outer membranes and, in many respects, resembles and functions like a syringe. This type III secretion apparatus (TTSA) is used to inject proteins into a host cell's membrane and cytoplasm to subvert normal cellular processes. The external portion of the TTSA is a needle that is composed of a single type of protein that is polymerized in a helical fashion to form an elongated tube with a central channel of 2-3 nm in diameter. TTSA needle proteins from a variety of bacterial pathogens share sequence conservation; however, no atomic structure for any TTSA needle protein is yet available. Here, we report the structure of a TTSA needle protein called BsaL from Burkholderia pseudomallei determined by nuclear magnetic resonance (NMR) spectroscopy. The central part of the protein assumes a helix-turn-helix core domain with two well-defined alpha-helices that are joined by an ordered, four-residue linker. This forms a two-helix bundle that is stabilized by interhelix hydrophobic contacts. Residues that flank this presumably exposed core region are not completely disordered, but adopt a partial helical conformation. The atomic structure of BsaL and its sequence homology with other TTSA needle proteins suggest potentially unique structural dynamics that could be linked with a universal mechanism for control of type III secretion in diverse gram-negative bacterial pathogens.

Selected figure(s)

Figure 3.
Figure 3. Secondary chemical shifts obtained by subtracting the random coil 13C^a, 1Ha, 13C^b, and 13C' chemical shift values from those observed in the protein indicate the presence of two well-defined helices in the middle of the protein.

Figure 4.
Figure 4. (a) Stereo view of the 20 lowest energy NMR structures of BsaLD5 showing residues Asp27-Ser72. Residues Lys30-Asn68 form the well-defined core domain of BsaLD5. The rest of the molecule does not adopt a single conformation and, therefore, will not superimpose. (b) Ribbon diagram of the lowest energy NMR structure of BsaLD5, showing the residues that form the hydrophobic contacts at the interface of helix a[1] and a[2]. ((c)-(e)) Surface representations showing the polar residues that line the surfaces of the core domain of BsaLD5. The side-chain functional groups of residues on the surface are colored as follows: amides blue, carboxyls and hydroxyls red, methylenes green, and the methionine sulfur atoms orange. The amino and carboxy termini are labeled N and C.

The above figures are reprinted by permission from Elsevier: J Mol Biol (2006, 359, 322-330) copyright 2006.

Figures were selected by an automated process.