Topological characterization of the essential Escherichia coli cell division protein FtsN.
AUTOR(ES)
Dai, K
RESUMO
Genetic and biochemical approaches were used to analyze a topological model for FtsN, a 36-kDa protein with a putative transmembrane segment near the N terminus, and to ascertain the requirements of the putative cytoplasmic and membrane-spanning domains for the function of this protein. Analysis of FtsN-PhoA fusions revealed that the putative transmembrane segment of FtsN could act as a translocation signal. Protease accessibility studies of FtsN in spheroblasts and inverted membrane vesicles confirmed that FtsN had a simple bitopic topology with a short cytoplasmic amino terminus, a single membrane-spanning domain, and a large periplasmic carboxy terminus. To ascertain the functional requirements of the N-terminal segments of FtsN, various constructs were made. Deletion of the N-terminal cytoplasmic and membrane-spanning domains led to intracellular localization of the carboxy domain, instability,and loss of function. Replacement of the N-terminal cytoplasmic and membrane-spanning domains with a membrane-spanning domain from MalG restored subcellular localization and function. These N-terminal domains of FtsN could also be replaced by the cleavable MalE signal sequence with restoration of subcellular localization and function. It is concluded that the N-terminal, cytoplasmic, and transmembrane domains of FtsN are not required for function of the carboxy domain other than to transport it to the periplasm. FtsQ and FtsI were also analyzed.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=177806Documentos Relacionados
- Murein (Peptidoglycan) Binding Property of the Essential Cell Division Protein FtsN from Escherichia coli
- Cloning and characterization of ftsN, an essential cell division gene in Escherichia coli isolated as a multicopy suppressor of ftsA12(Ts).
- Genetic Analysis of the Cell Division Protein FtsI (PBP3): Amino Acid Substitutions That Impair Septal Localization of FtsI and Recruitment of FtsN
- ZipA Is Required for Recruitment of FtsK, FtsQ, FtsL, and FtsN to the Septal Ring in Escherichia coli
- Septal Localization of FtsQ, an Essential Cell Division Protein in Escherichia coli