Functional regions of the Bacillus subtilis spore coat morphogenetic protein CotE.
The Bacillus subtilis spore is encased in a resilient, multilayered proteinaceous shell, called the coat, that protects it from the environment. A 181-amino-acid coat protein called CotE assembles into the coat early in spore formation and plays a morphogenetic role in the assembly of the coat's outer layer. We have used a series of mutant alleles of cotE to identify regions involved in outer coat protein assembly. We found that the insertion of a 10-amino-acid epitope, between amino acids 178 and 179 of CotE, reduced or prevented the assembly of several spore coat proteins, including, most likely, CotG and CotB. The removal of 9 or 23 of the C-terminal-most amino acids resulted in an unusually thin outer coat from which a larger set of spore proteins was missing. In contrast, the removal of 37 amino acids from the C terminus, as well as other alterations between amino acids 4 and 160, resulted in the absence of a detectable outer coat but did not prevent localization of CotE to the forespore. These results indicate that changes in the C-terminal 23 amino acids of CotE and in the remainder of the protein have different consequences for outer coat protein assembly.
Bauer
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T
Department of Microbiology, Loyola University Medical Center, Maywood, Illinois 60153, USA.
Little
S
S
Stöver
A G
AG
Driks
A
A
D001412:Bacillus subtilis / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D015153:Blotting, Western; D000939:Epitopes; D008854:Microscopy, Electron; D008856:Microscopy, Fluorescence; D009024:Morphogenesis; D017354:Point Mutation; D013171:Spores, Bacterial / Q000737:chemistry / Q000378:metabolism*
D001426:Bacterial Proteins; C077494:CotE protein, Bacillus subtilis; D000939:Epitopes