A plant MinD homologue rescues Escherichia coli HL1 mutant (ΔMinDE) in the absence of MinE

Min Zhang,Yikun He,Hongbo Gao,Jingjing Jia,Yong Hu

doi:10.1186/1471-2180-9-101

Min Zhang, Yikun He + Show 3 more

Open Access

https://doi.org/10.1186/1471-2180-9-101

Copy DOI

Abstract

BackgroundIn E. coli, the Min operon (MinCDE) plays a key role in determining the site of cell division. MinE oscillates from the middle to one pole or another to drive the MinCD complex to the end of the cell. The MinCD complex prevents FtsZ ring formation and the subsequent cell division at cell ends. In Arabidopsis thaliana, a homologue of MinD has been shown to be involved in the positioning of chloroplast division site.ResultsTo learn whether the MinD homologue in plants is functional in bacteria, AtMinD was expressed in E. coli. Surprisingly, AtMinD can rescue the minicell phenotype of E. coli HL1 mutant (ΔMinDE) in the absence of EcMinE. This rescue requires EcMinC. AtMinD was localized to puncta at the poles of E. coli cells and puncta in chloroplasts without oscillation. AtMinD expressed in the HL1 mutant can cause a punctate localization pattern of GFP-EcMinC at cell ends. Yeast two hybrid and BiFC analysis showed that AtMinD can interact with EcMinC.ConclusionSimilar to the MinD in Bacillus subtilis, AtMinD is localized to the polar region in E. coli and interacts with EcMinC to confine EcFtsZ polymerization and cell division at the midpoint of the cell.

Highlights

In E. coli, the Min operon (MinCDE) plays a key role in determining the site of cell division
A MinD homologue from Arabidopsis complements the minicell mutant phenotype of E. coli HL1 mutant (ΔMinDE) in the absence of MinE The E. coli HL1 mutant (ΔMinDE) has an apparent minicell phenotype with 30.5% of the cells are shorter than 2 μm and 38.1% of the cells are between 2 μm to 5 μm (Figure 1B and Table 1)
The mutant phenotype of HL1 mutant was complemented by a pM1113MinDE plasmid with 20 μM IPTG (Figure 1C and Table 1), which was used for the induction of MinD and MinE

Summary

Introduction

In E. coli, the Min operon (MinCDE) plays a key role in determining the site of cell division. The MinCD complex prevents FtsZ ring formation and the subsequent cell division at cell ends. In Escherichia coli, proper positioning of the cell division apparatus at midpoint of the cell is mainly controlled by Min operon, which encodes MinC, MinD and MinE [1]. MinD [7], which results in release of MinC and conversion of membrane-bound MinD (MinD:ATP) to cytoplasmic MinD (MinD:ADP) [7]. This highly dynamic localization cycle of Min proteins inhibits FtsZ ring formation near cell ends and forces FtsZ and many other cell division proteins to assembly at the center of the cell [8]. FtsZ and Min proteins are conserved in a wide variety of bacteria, including cyanobacteria [9]

Methods

Results

Conclusion