The MinD Membrane Targeting Sequence Is a Transplantable Lipid-binding Helix

Tim H Szeto,Susan L Rowland,Cheryl L Habrukowich,Glenn F King

doi:10.1074/jbc.m306876200

Tim H Szeto, Susan L Rowland + Show 2 more

Open Access

https://doi.org/10.1074/jbc.m306876200

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Abstract

MinD is a ubiquitous ATPase that plays a crucial role in selection of the division site in eubacteria, chloroplasts, and probably also Archaea. It was recently demonstrated that membrane localization of MinD is mediated by an 8-12-residue C-terminal motif termed the membrane targeting sequence or MTS. In this study we show that the MinD MTS is a transplantable lipid-binding motif that can effectively target heterologous proteins to the cell membrane. We demonstrate that eubacterial MTSs interact directly with lipid bilayers as an amphipathic helix, with a distinct preference for anionic phospholipids. Moreover, we provide evidence that the phospholipid preference of each MTS, as well as its affinity for biological membranes, has been evolutionarily "tuned" to its specific role in different bacteria. We propose a model to describe how the MTS is coupled to ATP binding to regulate the reversible membrane association of Escherichia coli MinD during its pole-to-pole oscillation cycle.

Highlights

The initiating event in bacterial cytokinesis is the formation of a circumferential ring of polymerized FtsZ, the ancestral homolog of eukaryotic tubulin [1,2,3]
In B. subtilis, the MinCD complex is anchored at the cell poles by DivIVA where it remains throughout the cell cycle until a late stage in assembly of the division apparatus when it is piloted to the nascent division site (16 –18)
We initially examined the interaction of MTS peptides with SUVs containing a mixture of lipids (70% PE, 20% PG, 10% CL) that approximated the known phospholipid ratio in the E. coli inner membrane [39, 40]; we refer to these as “wild-type” SUVs (WT-SUVs)

Summary

Introduction

The initiating event in bacterial cytokinesis is the formation of a circumferential ring of polymerized FtsZ, the ancestral homolog of eukaryotic tubulin [1,2,3]. In this study we show that the MinD MTS is a transplantable lipid-binding motif that can effectively target heterologous proteins to the cell membrane.

Results

Conclusion