Backbone and side-chain (1)H, (13)C, and (15)N NMR assignments of the N-terminal domain of Escherichia coli LpoA.

The peptidoglycan is a major component of the bacterial cell wall and is essential to maintain cellular integrity and cell shape. Penicillin-Binding Proteins (PBPs) catalyze the final biosynthetic steps of peptidoglycan synthesis from lipid II precursor and are the main targets of β-lactam antibiotics. The molecular details of peptidoglycan growth and its regulation are poorly understood. Presumably, PBPs are active in peptidoglycan synthesizing multi-enzyme complexes that are controlled from inside the cell by cytoskeletal elements. Recently, two outer-membrane lipoproteins, LpoA and LpoB, were shown to be required in Escherichia coli for the function of the main peptidoglycan synthases, PBP1A and PBP1B, by stimulating their transpeptidase activity. However, the mechanism of PBP-activation by Lpo proteins is not known, and the Lpo proteins await structural characterization at atomic resolution. Here we present the backbone and side-chain (1)H, (13)C, (15)N NMR assignments of the N-terminal domain of LpoA from E. coli for structural and functional studies.