Abstract
The peptidoglycan cell wall is an integral organelle critical for bacterial cell shape and stability. Proper cell wall construction requires the interaction of synthesis enzymes and the cytoskeleton, but it is unclear how the activities of individual proteins are coordinated to preserve the morphology and integrity of the cell wall during growth. To elucidate this coordination, we used single-molecule imaging to follow the behaviours of the two major peptidoglycan synthases in live, elongating Escherichia coli cells and after perturbation. We observed heterogeneous localization dynamics of penicillin-binding protein (PBP) 1A, the synthase predominantly associated with cell wall elongation, with individual PBP1A molecules distributed between mobile and immobile populations. Perturbations to PBP1A activity, either directly through antibiotics or indirectly through PBP1A's interaction with its lipoprotein activator or other synthases, shifted the fraction of mobile molecules. Our results suggest that multiple levels of regulation control the activity of enzymes to coordinate peptidoglycan synthesis.
Publication types
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Research Support, N.I.H., Extramural
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Research Support, U.S. Gov't, Non-P.H.S.
MeSH terms
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Amdinocillin / pharmacology
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Ampicillin / pharmacology
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Anti-Bacterial Agents / pharmacology
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Cefmetazole / pharmacology
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Cefsulodin / pharmacology
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Cell Wall / chemistry
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Cell Wall / drug effects
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Cell Wall / metabolism*
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Cell Wall / ultrastructure
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Diffusion
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Escherichia coli / drug effects
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Escherichia coli / genetics
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Escherichia coli / metabolism*
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Escherichia coli / ultrastructure
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Escherichia coli Proteins / genetics
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Escherichia coli Proteins / metabolism*
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Gene Expression Regulation, Bacterial*
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Penicillin-Binding Proteins / genetics
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Penicillin-Binding Proteins / metabolism*
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Peptidoglycan / biosynthesis*
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Peptidoglycan / genetics
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Peptidoglycan Glycosyltransferase / genetics
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Peptidoglycan Glycosyltransferase / metabolism*
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Serine-Type D-Ala-D-Ala Carboxypeptidase / genetics
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Serine-Type D-Ala-D-Ala Carboxypeptidase / metabolism*
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Single Molecule Imaging / methods
Substances
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Anti-Bacterial Agents
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Escherichia coli Proteins
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Penicillin-Binding Proteins
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Peptidoglycan
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Cefmetazole
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Ampicillin
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Peptidoglycan Glycosyltransferase
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penicillin-binding protein 1A, E coli
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penicillin-binding protein 1B, E coli
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Serine-Type D-Ala-D-Ala Carboxypeptidase
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Cefsulodin
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Amdinocillin