2MII

NMR structure of E. coli LpoB

Summary for 2MII

• Entry DOI: 10.2210/pdb2mii/pdb
• NMR Information: BMRB: 19681
• Descriptor: Penicillin-binding protein activator LpoB (1 entity in total)
• Functional Keywords: lpob, pbp1b activator, peptidoglycan synthesis, protein binding
• Biological source: Escherichia coli
• Cellular location: Cell outer membrane; Lipid-anchor; Periplasmic side (By similarity): B1XA15
• Total number of polymer chains: 1
• Total formula weight: 20770.30

Authors

Jean, N.L.,Egan, A.J.F.,Koumoutsi, A.,Bougault, C.M.,Typas, A.,Vollmer, W.,Simorre, J.P. (deposition date: 2013-12-13, release date: 2014-05-21, Last modification date: 2024-05-15)

Primary citation

Egan, A.J.,Jean, N.L.,Koumoutsi, A.,Bougault, C.M.,Biboy, J.,Sassine, J.,Solovyova, A.S.,Breukink, E.,Typas, A.,Vollmer, W.,Simorre, J.P.
Outer-membrane lipoprotein LpoB spans the periplasm to stimulate the peptidoglycan synthase PBP1B.
Proc.Natl.Acad.Sci.USA, 111:8197-8202, 2014

PubMed Abstract: Bacteria surround their cytoplasmic membrane with an essential, stress-bearing peptidoglycan (PG) layer. Growing and dividing cells expand their PG layer by using membrane-anchored PG synthases, which are guided by dynamic cytoskeletal elements. In Escherichia coli, growth of the mainly single-layered PG is also regulated by outer membrane-anchored lipoproteins. The lipoprotein LpoB is required for the activation of penicillin-binding protein (PBP) 1B, which is a major, bifunctional PG synthase with glycan chain polymerizing (glycosyltransferase) and peptide cross-linking (transpeptidase) activities. Here, we report the structure of LpoB, determined by NMR spectroscopy, showing an N-terminal, 54-aa-long flexible stretch followed by a globular domain with similarity to the N-terminal domain of the prevalent periplasmic protein TolB. We have identified the interaction interface between the globular domain of LpoB and the noncatalytic UvrB domain 2 homolog domain of PBP1B and modeled the complex. Amino acid exchanges within this interface weaken the PBP1B-LpoB interaction, decrease the PBP1B stimulation in vitro, and impair its function in vivo. On the contrary, the N-terminal flexible stretch of LpoB is required to stimulate PBP1B in vivo, but is dispensable in vitro. This supports a model in which LpoB spans the periplasm to interact with PBP1B and stimulate PG synthesis.

PubMed: 24821816
DOI: 10.1073/pnas.1400376111

Experimental method

SOLUTION NMR