The gene bolA regulates dacA (PBP5), dacC (PBP6) and ampC (AmpC), promoting normal morphology in Escherichia coli

Authors

  • Jorge M. Santos,

    Corresponding author
    1. Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Oeiras, Portugal.
    • For correspondence. E-mail Cecilia@ itqb.unl.pt ; Tel. (+351) 214 469 547; Fax (+351) 214 411 277. Present address: Laboratório de Genómica Funcional, Departmento de Biologia, Universidade de Aveiro, Aveiro, Portugal.

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  • Mónica Lobo,

    1. Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Oeiras, Portugal.
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  • António P. A. Matos,

    1. Serviço de Anatomia Patológica, Hospital Curry Cabral, Lisboa, Portugal
    2. Departamento de Biomateriais, Faculdade Medicina Dentária, Universidade de Lisboa, Lisboa, Portugal.
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  • Miguel A. De Pedro,

    1. Centro de Biologia Molecular Severo Ochoa, Consejo Superior de Investigaciones Cientificas, Universidad Autonoma de Madrid, Campus de Cantoblanco, Madrid, Spain.
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  • Cecilia M. Arraiano

    Corresponding author
    1. Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Oeiras, Portugal.
    • For correspondence. E-mail Cecilia@ itqb.unl.pt ; Tel. (+351) 214 469 547; Fax (+351) 214 411 277. Present address: Laboratório de Genómica Funcional, Departmento de Biologia, Universidade de Aveiro, Aveiro, Portugal.

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Summary

The gene bolA has been shown to trigger the formation of osmotically stable round cells when overexpressed in stationary phase. We show that in poor growth conditions bolA is essential for normal cell morphology in stationary phase and under conditions of starvation. During exponential growth bolA promotes round morphology through a mechanism that is strictly dependent on the two main Escherichia colid,d-carboxypeptidases, PBP5 and PBP6. The results show that bolA controls the levels of transcription of dacA (PBP5), dacC (PBP6) and ampC (AmpC), a class C β-lactamase, thus connecting for the first time penicillin binding proteins (PBPs) and β-lactamases at the level of gene regulation. Furthermore, PBP5 and PBP6 are shown to be independently regulated and to have distinct effects on the peptidoglycan layer. The evidence presented demonstrates that bolA is a regulator of cell wall biosynthetic enzymes with different roles in cell morphology and cell division.

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