Modulation of Escherichia coli Cell Membrane by a Monotopic Lipid Glycosyltransferase - an Exploration of Potential Mechanisms

• Intracellular vesicles are abundant in eukaryotic cells but are rare in Gram-negative bacterium Escherichia coli. Strongly overexpression of a monotopic glycolipid-synthesizing enzyme could induce massive formation of “foreign” vesicles in the cytoplasm. Here we investigate how this membrane-associated enzyme is able to bend and deform the plasma membrane. Limited proteolysis combined with ESI-MS suggested interface binding is mediated through both its two Rossmann fold topological domains. Detailed subcellular localization and liposome binding assay indicates different interface anchoring regions in the protein, and anionic lipid seems to influence the binding properties of the anchoring segments. Genetic engineering of a known membrane-bound segment to explore its vesiculation potentials led to the identification of important catalytic residues (regions). Flow cytometry and infrared spectroscopy were also performed on bacterial cells to get more insight into the cellular morphology and internal complexity. The linking region between two domains was demonstrated to be crucial for both catalytic function and vesiculation capacity of the enzyme. Based on our findings, we propose, that scaffold-like structural feature of this enzyme is most likey one of key elements contributing to vesiculation.        

Ämnesord

NATURVETENSKAP  -- Biologi -- Biokemi och molekylärbiologi (hsv//swe)

NATURAL SCIENCES  -- Biological Sciences -- Biochemistry and Molecular Biology (hsv//eng)

Nyckelord

Biochemistry

Biokemi

Biochemistry

biokemi

Publikations- och innehållstyp

vet (ämneskategori)

ovr (ämneskategori)