Localization of FtsI (PBP3) to the septal ring requires its membrane anchor, the Z ring, FtsA, FtsQ, and FtsL.
J Bacteriol
; 181(2): 508-20, 1999 Jan.
Article
em En
| MEDLINE
| ID: mdl-9882665
ABSTRACT
Assembly of the division septum in bacteria is mediated by several proteins that localize to the division site. One of these, FtsI (also called penicillin-binding protein 3) of Escherichia coli, consists of a short cytoplasmic domain, a single membrane-spanning segment, and a large periplasmic domain that encodes a transpeptidase activity involved in synthesis of septal peptidoglycan. We have constructed a merodiploid strain with a wild-type copy of ftsI at the normal chromosomal locus and a genetic fusion of ftsI to the green fluorescent protein (gfp) at the lambda attachment site. gfp-ftsI was expressed at physiologically appropriate levels under control of a regulatable promoter. Consistent with previous results based on immunofluorescence microscopy GFP-FtsI localized to the division site during the later stages of cell growth and throughout septation. Localization of GFP-FtsI to the cell pole(s) was not observed unless the protein was overproduced about 10-fold. Membrane anchor alterations shown previously to impair division but not membrane insertion or transpeptidase activity were found to interfere with localization of GFP-FtsI to the division site. In contrast, GFP-FtsI localized well in the presence of beta-lactam antibiotics that inhibit the transpeptidase activity of FtsI. Septal localization depended upon every other division protein tested (FtsZ, FtsA, FtsQ, and FtsL). We conclude that FtsI is a late recruit to the division site, and that its localization depends on an intact membrane anchor.
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Base de dados:
MEDLINE
Assunto principal:
Proteínas de Bactérias
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Muramilpentapeptídeo Carboxipeptidase
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Proteínas de Transporte
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Peptidil Transferases
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Proteínas de Ciclo Celular
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Proteínas de Escherichia coli
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Peptidoglicano Glicosiltransferase
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Escherichia coli
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Hexosiltransferases
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Proteínas de Membrana
Idioma:
En
Ano de publicação:
1999
Tipo de documento:
Article