1. The bacterial cell division protein fragment EFtsN binds to and activates the major peptidoglycan synthase PBP1b
- Author
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Boes, Adrien, Kerff, Frédéric, Herman, Raphael, Touzé, Thierry, Breukink, Eefjan, Terrak, Mohammed, Institut de Biologie Intégrative de la Cellule (I2BC), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Enveloppes Bactériennes et Antibiotiques (ENVBAC), Département Microbiologie (Dpt Microbio), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Institut de Biologie Intégrative de la Cellule (I2BC), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Sub Membrane Biochemistry & Biophysics, and Membrane Biochemistry and Biophysics
- Subjects
cell division ,FtsN ,cellular regulation ,Escherichia coli Proteins ,[SDV]Life Sciences [q-bio] ,penicillin-binding protein 1b (PBP1b) ,Membrane Proteins ,lipid II ,Peptidoglycan ,Microbiology ,Serine-Type D-Ala-D-Ala Carboxypeptidase ,cell surface enzyme ,PBP1b ,eptidoglycan ,Lipid II ,Escherichia coli ,Penicillin-Binding Proteins ,cell wall ,Peptidoglycan Glycosyltransferase ,divisome ,bacteria ,Divisome ,Protein Binding - Abstract
Peptidoglycan (PG) is an essential constituent of the bacterial cell wall. During cell division, the machinery responsible for PG synthesis localizes mid-cell, at the septum, under the control of a multiprotein complex called the divisome. In Escherichia coli , septal PG synthesis and cell constriction rely on the accumulation of FtsN at the division site. Interestingly, a short sequence of FtsN (L75 to Q93, known as E FtsN) was shown to be essential and sufficient for its functioning in vivo , but what exactly this sequence is doing remained unknown. Here, we show that E FtsN binds specifically to the major PG synthase PBP1b and is sufficient to stimulate its biosynthetic glycosyltransferase (GTase) activity. We also report the crystal structure of PBP1b in complex with E FtsN, which demonstrates E FtsN binds at the junction between the GTase and UB2H domains of PBP1b. Interestingly, mutations to two residues (R141A/R397A) within the E FtsN binding pocket reduced the activation of PBP1b by FtsN but not by the lipoprotein LpoB. This mutant was unable to rescue Δ pon B- pon Ats strain, that lack PBP1b and has a thermosensitive PBP1a, at nonpermissive temperature and induced a mild cell chaining phenotype and cell lysis. Altogether, the results show that E FtsN interacts with PBP1b and that this interaction plays a role in the activation of its GTase activity by FtsN, which may contribute to the overall septal PG synthesis and regulation during cell division.
- Published
- 2020