6TPI

EnvC bound to the FtsX periplasmic domain

Summary for 6TPI

• Entry DOI: 10.2210/pdb6tpi/pdb
• Descriptor: Murein hydrolase activator EnvC, Cell division protein FtsX (3 entities in total)
• Functional Keywords: complex, protein binding
• Biological source: Escherichia coli (strain K12); More
• Total number of polymer chains: 3
• Total formula weight: 67642.52

Authors

Crow, A. (deposition date: 2019-12-13, release date: 2020-11-04, Last modification date: 2024-01-24)

Primary citation

Cook, J.,Baverstock, T.C.,McAndrew, M.B.L.,Stansfeld, P.J.,Roper, D.I.,Crow, A.
Insights into bacterial cell division from a structure of EnvC bound to the FtsX periplasmic domain.
Proc.Natl.Acad.Sci.USA, 117:28355-28365, 2020

PubMed Abstract: FtsEX is a bacterial ABC transporter that regulates the activity of periplasmic peptidoglycan amidases via its interaction with the murein hydrolase activator, EnvC. In , FtsEX is required to separate daughter cells after cell division and for viability in low-osmolarity media. Both the ATPase activity of FtsEX and its periplasmic interaction with EnvC are required for amidase activation, but the process itself is poorly understood. Here we present the 2.1 Å structure of the FtsX periplasmic domain in complex with its periplasmic partner, EnvC. The EnvC-FtsX periplasmic domain complex has a 1-to-2 stoichiometry with two distinct FtsX-binding sites located within an antiparallel coiled coil domain of EnvC. Residues involved in amidase activation map to a previously identified groove in the EnvC LytM domain that is here found to be occluded by a "restraining arm" suggesting a self-inhibition mechanism. Mutational analysis, combined with bacterial two-hybrid screens and in vivo functional assays, verifies the FtsEX residues required for EnvC binding and experimentally test a proposed mechanism for amidase activation. We also define a predicted link between FtsEX and integrity of the outer membrane. Both the ATPase activity of FtsEX and its periplasmic interaction with EnvC are required for resistance to membrane-attacking antibiotics and detergents to which would usually be considered intrinsically resistant. These structural and functional data provide compelling mechanistic insight into FtsEX-mediated regulation of EnvC and its downstream control of periplasmic peptidoglycan amidases.

PubMed: 33097670
DOI: 10.1073/pnas.2017134117

Experimental method

X-RAY DIFFRACTION (2.1 Å)