PDBsum entry 1w2e

Bacterial cell division

PDB id: 1w2e

Contents

Protein chains

92 a.a. *

Waters ×12

* Residue conservation analysis

PDB id:

1w2e

Name:

Bacterial cell division

Title:

The crystal structure of the bacterial cell division protein zapa

Structure:

Zapa. Chain: a, b. Synonym: hypothetical protein pa5227. Engineered: yes

Source:

Pseudomonas aeruginosa. Organism_taxid: 287. Strain: pa01-lac. Atcc: 47085d. Expressed in: escherichia coli bl21(de3). Expression_system_taxid: 469008. Expression_system_variant: c41.

Biol. unit:

Tetramer (from PDB file)

Resolution:

2.80Å R-factor: 0.240 R-free: 0.289

Authors:

H.H.Low,M.C.Moncrieffe,J.Lowe

Key ref:

H.H.Low et al. (2004). The crystal structure of ZapA and its modulation of FtsZ polymerisation. J Mol Biol, 341, 839-852. PubMed id: 15288790 DOI: 10.1016/j.jmb.2004.05.031

Date:

01-Jul-04 Release date: 19-Jul-04

Protein chains

Q9HTW3  (ZAPA_PSEAE) -  Cell division protein ZapA from Pseudomonas aeruginosa (strain ATCC 15692 / DSM 22644 / CIP 104116 / JCM 14847 / LMG 12228 / 1C / PRS 101 / PAO1)

Seq: 104 a.a.

Struc: 92 a.a.

DOI no: 10.1016/j.jmb.2004.05.031

J Mol Biol 341:839-852 (2004)

PubMed id: 15288790

The crystal structure of ZapA and its modulation of FtsZ polymerisation.

H.H.Low, M.C.Moncrieffe, J.Löwe.

ABSTRACT

FtsZ is part of a mid-cell cytokinetic structure termed the Z-ring that recruits a hierarchy of fission related proteins early in the bacterial cell cycle. The widely conserved ZapA has been shown to interact with FtsZ, to drive its polymerisation and to promote FtsZ filament bundling thereby contributing to the spatio-temporal tuning of the Z-ring. Here, we show the crystal structure of ZapA (11.6 kDa) from Pseudomonas aeruginosa at 2.8 A resolution. The electron density reveals two dimers associating via an extensive C-terminal coiled-coil protrusion to form an elongated anti-parallel tetramer. In solution, ZapA exists in a dimer-tetramer equilibrium that is strongly correlated with concentration. An increase in concentration promotes formation of the higher oligomeric state. The dimer is postulated to be the predominant physiological species although the tetramer could become significant if, as FtsZ is integrated into the Z-ring and is cross-linked, the local concentration of the dimer becomes sufficiently high. We also show that ZapA binds FtsZ with an approximate 1:1 molar stoichiometry and that this interaction provokes dramatic FtsZ polymerisation and inter-filament association as well as yielding filaments, single or bundled, more stable and resistant to collapse. Whilst in vitro dynamics of FtsZ are well characterised, its in vivo arrangement within the ultra-structural architecture of the Z-ring is yet to be determined despite being fundamental to cell division. The ZapA dimer has single 2-fold symmetry whilst the bipolar tetramer displays triple 2-fold symmetry. Given the symmetry of these ZapA oligomers and the polar nature of FtsZ filaments, the structure of ZapA carries novel implications for the inherent architecture of the Z-ring in vivo.

Selected figure(s)

Figure 3.
Figure 3. Stereo image showing the conformation of the four H2 helices in a ZapA tetramer with their side-chains exposed. The tetramerisation domain is formed by extensive overlap between the C termini of the H2 helices. This region is characterised by a central hydrophobic core and surrounding hydrophilic amino acid residues with interdigitating side-chains. In contrast, the dimerisation domain is located towards the opposite ends of the H2 helices with inter-helix proximity and contact increasing towards the N termini.

Figure 6.
Figure 6. A, Surface map displaying the electrostatic potential of the ZapA dimer. Coloured from -6.0 kT/e, red to 6.0 kT/e, blue. Orientation is similar to subunits AB in Figure 2B. B, A grading of inter-species residue conservation from 25 ZapA sequences; a spectrum from red, highly conserved through to dark blue, least conserved. Orientation is similar to subunits AB in Figure 2B.

The above figures are reprinted by permission from Elsevier: J Mol Biol (2004, 341, 839-852) copyright 2004.

Figures were selected by an automated process.