Bacterial amidases are essential to split the shared envelope of adjunct daughter cells to allow cell separation. Their activity needs to be precisely controlled to prevent cell lysis. In Escherichia coli, amidase activity is controlled by three regulatory proteins NlpD, EnvC and ActS. However, recent studies linked the outer membrane lipoprotein DolP (formerly YraP) as a potential upstream regulator of NlpD. In this study we explored this link in further detail. To our surprise DolP did not modulate amidase activity in vitro and was unable to interact with NlpD in pull-down and MST (MicroScale Thermophoresis) assays. Next, we excluded the hypothesis that Δ dolP phenocopied Δ nlpD in a range of envelope stresses. However, morphological analysis of double deletion mutants of amidases (AmiA, AmiB AmiC) and amidase regulators with dolP revealed that Δ amiAΔ dolP and Δ envCΔ dolP mutants display longer chain length compared to their parental strains indicating a role for DolP in cell division. Overall, we present evidence that DolP does not affect NlpD function in vitro, implying that DolP is not an upstream regulator of NlpD. However, DolP may impact daughter cell separation by interacting directly with AmiA or AmiC, or by a yet undiscovered mechanism.
Bibliographical noteFunding Information:
G.B. and M.A were supported by a PhD studentship from the Darwin Trust of Edinburgh. M.B was supported by a UKRI Future Leaders Fellowship [MR/V027204/1]. H.D. was supported by the Wellcome Trust AAMR DTP. M.G. is supported by the National Science Centre Poland [UMO-2017/27/B/ NZ2/00747].
© 2022 The Authors.
- Bacterial Proteins/genetics
- Cell Separation
- Escherichia coli/metabolism
- Escherichia coli Proteins/genetics
- bacterial cell division
- Gram-negative cell envelope
ASJC Scopus subject areas