Abstract
In order to divide, the bacterium Escherichia coli must assemble a set of at least 10 essential proteins at the nascent division site. These proteins localize to midcell according to a linear hierarchy, suggesting that cell division proteins are added to the nascent divisome in strict sequence. We previously described a method, 'premature targeting', which allows us to target a protein directly to the division site independently of other cell division proteins normally required for its localization at midcell. By systematically applying this method to probe the recruitment of and associations among late cell division proteins, we show that this linear assembly model is likely incorrect. Rather, we find that the assembly of most of the late proteins can occur independently of 'upstream' proteins. Further, most late proteins, when prematurely targeted to midcell, can back-recruit upstream proteins in the reverse of the predicted pathway. Together these observations indicate that the late proteins, with the notable exception of the last protein in the pathway, FtsN, are associated in a hierarchical set of protein complexes. Based on these observations we present a revised model for assembly of the E. coli division apparatus.
Publication types
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Research Support, N.I.H., Extramural
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Research Support, Non-U.S. Gov't
MeSH terms
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Bacterial Proteins / genetics
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Bacterial Proteins / metabolism
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Bacterial Proteins / physiology
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Cell Cycle Proteins / genetics
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Cell Cycle Proteins / metabolism
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Cell Cycle Proteins / physiology*
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Cell Division / genetics
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Cell Division / physiology
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Escherichia coli / cytology
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Escherichia coli / genetics
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Escherichia coli / physiology*
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Escherichia coli Proteins / genetics
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Escherichia coli Proteins / metabolism
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Escherichia coli Proteins / physiology*
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Membrane Proteins / genetics
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Membrane Proteins / metabolism
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Membrane Proteins / physiology
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Microscopy, Fluorescence
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Models, Biological
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Multiprotein Complexes / genetics
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Multiprotein Complexes / metabolism
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Multiprotein Complexes / physiology
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Penicillin-Binding Proteins / genetics
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Penicillin-Binding Proteins / metabolism
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Penicillin-Binding Proteins / physiology
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Peptidoglycan Glycosyltransferase / genetics
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Peptidoglycan Glycosyltransferase / metabolism
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Peptidoglycan Glycosyltransferase / physiology
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Protein Binding
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Recombinant Fusion Proteins / genetics
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Recombinant Fusion Proteins / metabolism
Substances
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Bacterial Proteins
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Cell Cycle Proteins
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Escherichia coli Proteins
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FtsB protein, E coli
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FtsI protein, E coli
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FtsQ protein, E coli
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Membrane Proteins
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Multiprotein Complexes
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Penicillin-Binding Proteins
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Recombinant Fusion Proteins
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ftsL protein, E coli
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FtsW protein, Bacteria
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Peptidoglycan Glycosyltransferase