ISSN:
1365-2958
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Biology
,
Medicine
Notes:
Correct placement of the division septum in Escherichia coli requires the co-ordinated action of three proteins, MinC, MinD and MinE. MinC and MinD interact to form a non-specific division inhibitor that blocks septation at all potential division sites. MinE is able to antagonize MinCD in a topologically sensitive manner, as it restricts MinCD activity to the unwanted division sites at the cell poles. Here, we show that the topological specificity function of MinE residues in a structurally autonomous, trypsin-resistant domain comprising residues 31–88. Nuclear magnetic resonance (NMR) and circular dichroic spectroscopy indicate that this domain includes both α and β secondary structure, while analytical ultracentrifugation reveals that it also contains a region responsible for MinE homodimerization. While trypsin digestion indicates that the anti-MinCD domain of MinE (residues 1–22) does not form a tightly folded structural domain, NMR analysis of a peptide corresponding to MinE1–22 indicates that this region forms a nascent helix in which the peptide rapidly interconverts between disordered (random coil) and α-helical conformations. This suggests that the N-terminal region of MinE may be poised to adopt an α-helical conformation when it interacts with the target of its anti-MinCD activity, presumably MinD.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1046/j.1365-2958.1999.01256.x
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