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Localization of the Escherichia coli cell division protein FtsI (PBP3) to the division site and cell pole
Journal article   Open access   Peer reviewed

Localization of the Escherichia coli cell division protein FtsI (PBP3) to the division site and cell pole

David S Weiss, Kit Pogliano, Michael Carson, Luz‐Maria Guzman, Claudine Fraipont, Martine Nguyen‐Distèche, Richard Losick and Jon Beckwith
Molecular microbiology, Vol.25(4), pp.671-681
08/1997
DOI: 10.1046/j.1365-2958.1997.5041869.x
PMID: 9379897
url
https://doi.org/10.1046/j.1365-2958.1997.5041869.xView
Published (Version of record) Open Access

Abstract

FtsI, also known as penicillin-binding protein 3, is a transpeptidase required for the synthesis of peptidoglycan in the division septum of the bacterium, Escherichia coli. FtsI has been estimated to be present at about 100 molecules per cell, well below the detection limit of immunoelectron microscopy. Here, we confirm the low abundance of FtsI and use immunofluorescence microscopy, a highly sensitive technique, to show that FtsI is localized to the division site during the later stages of cell growth. FtsI was also sometimes observed at the cell pole; polar localization was not anticipated and its significance is not known. We conclude (i) that immunofluorescence microscopy can be used to localize proteins whose abundance is as low as approximately 100 molecules per cell; and (ii) that spatial and temporal regulation of FtsI activity in septum formation is achieved, at least in part, by timed localization of the protein to the division site.

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