Abstract:
:Chemotaxis is the process by which cells sense changes in their chemical environment and move towards more favorable conditions. In divergent species of bacteria, the chemotaxis proteins localize to the poles of the cell and information is transferred to the flagellar motors through the phosphorylation of a soluble protein CheY. Using mathematical models and computer simulation, we demonstrate that phosphatase localization controls the spatial distribution of CheY-P in the cytosol at steady state. Remarkably, the location of the phosphatase is not conserved in different species of bacteria. The sole phosphatase in Escherichia coli is localized with the signaling complex and the primary phosphatase in Bacillus subtilis is localized at the flagellar motors. Despite these alternate pathway structures, both designs minimize differences in the concentration of phosphorylated CheY proximal to each motor unlike a design where the phosphatase is freely diffusing in the cytoplasm. These results suggest that motile bacteria have evolved alternate mechanisms to ensure that each motor receives roughly the same signal at steady state. The hypothesis is that complex networks have evolved to satisfy certain design principles in order to function robustly. While specific mechanisms are different, the underlying principles of phosphatase localization in E. coli and B. subtilis appear to be the same.
journal_name
Phys Bioljournal_title
Physical biologyauthors
Rao CV,Kirby JR,Arkin APdoi
10.1088/1478-3975/2/3/002keywords:
subject
Has Abstractpub_date
2005-07-14 00:00:00pages
148-58issue
3eissn
1478-3967issn
1478-3975pii
S1478-3975(05)95962-1journal_volume
2pub_type
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