6YN0 image
Entry Detail
PDB ID:
6YN0
Keywords:
Title:
Structure of E. coli PBP1b with a FtsN peptide activating transglycosylase activity
Biological Source:
Host Organism:
PDB Version:
Deposition Date:
2020-04-10
Release Date:
2020-11-04
Method Details:
Experimental Method:
Resolution:
2.40 Å
R-Value Free:
0.25
R-Value Work:
0.22
R-Value Observed:
0.22
Space Group:
P 21 21 2
Macromolecular Entities
Polymer Type:polypeptide(L)
Description:Penicillin-binding protein 1B
Chain IDs:A
Chain Length:747
Number of Molecules:1
Biological Source:Escherichia coli (strain K12)
Polymer Type:polypeptide(L)
Description:Cell division protein FtsN
Chain IDs:B
Chain Length:19
Number of Molecules:1
Biological Source:Escherichia coli (strain K12)
Ligand Molecules
Primary Citation
The bacterial cell division protein fragment E FtsN binds to and activates the major peptidoglycan synthase PBP1b.
J.Biol.Chem. 295 18256 18265 (2020)
PMID: 33109614 DOI: 10.1074/jbc.RA120.015951

Abstact

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 (Leu75-Gln93, known as EFtsN) 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 EFtsN 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 EFtsN, which demonstrates that EFtsN binds at the junction between the GTase and UB2H domains of PBP1b. Interestingly, mutations to two residues (R141A/R397A) within the EFtsN-binding pocket reduced the activation of PBP1b by FtsN but not by the lipoprotein LpoB. This mutant was unable to rescue the ΔponB-ponAts strain, which lacks PBP1b and has a thermosensitive PBP1a, at nonpermissive temperature and induced a mild cell-chaining phenotype and cell lysis. Altogether, the results show that EFtsN 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.

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