1W2E

The Crystal Structure of the Bacterial Cell Division Protein ZapA

Summary for 1W2E

• Entry DOI: 10.2210/pdb1w2e/pdb
• Related: 1T3U
• Descriptor: ZAPA (2 entities in total)
• Functional Keywords: bacterial cell division, ftsz modulator
• Biological source: PSEUDOMONAS AERUGINOSA
• Cellular location: Cytoplasm : Q9HTW3
• Total number of polymer chains: 2
• Total formula weight: 23627.54

Authors

Low, H.H.,Moncrieffe, M.C.,Lowe, J. (deposition date: 2004-07-01, release date: 2004-07-19, Last modification date: 2024-10-23)

Primary citation

Low, H.H.,Moncrieffe, M.C.,Lowe, J.
The Crystal Structure of Zapa and its Modulation of Ftsz Polymerisation
J.Mol.Biol., 341:839-, 2004

PubMed 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.

PubMed: 15288790
DOI: 10.1016/J.JMB.2004.05.031

Experimental method

X-RAY DIFFRACTION (2.8 Å)