5KCN

Crystal Structure of full-length LpoA from Haemophilus influenzae at 1.97 angstrom resolution

Summary for 5KCN

• Entry DOI: 10.2210/pdb5kcn/pdb
• Related: 3CKM 4P29 5VAT 5VBG
• Descriptor: Penicillin-binding protein activator LpoA, CHLORIDE ION (3 entities in total)
• Functional Keywords: outer membrane lipoprotein, pbp1a, transpeptidase. peptidoglycan, biosynthetic protein
• Biological source: Haemophilus influenzae
• Total number of polymer chains: 1
• Total formula weight: 60045.53

Authors

Sathiyamoorthy, K.,Saper, M.A. (deposition date: 2016-06-06, release date: 2017-09-13, Last modification date: 2024-11-13)

Primary citation

Sathiyamoorthy, K.,Vijayalakshmi, J.,Tirupati, B.,Fan, L.,Saper, M.A.
Structural analyses of the Haemophilus influenzae peptidoglycan synthase activator LpoA suggest multiple conformations in solution.
J. Biol. Chem., 292:17626-17642, 2017

PubMed Abstract: In many Gram-negative bacteria, the peptidoglycan synthase PBP1A requires the outer membrane lipoprotein LpoA for constructing a functional peptidoglycan required for bacterial viability. Previously, we have shown that the C-terminal domain of LpoA (LpoA) has a highly conserved, putative substrate-binding cleft between two α/β lobes. Here, we report a 2.0 Å resolution crystal structure of the LpoA N-terminal domain. Two subdomains contain tetratricopeptide-like motifs that form a concave groove, but their relative orientation differs by ∼45° from that observed in an NMR structure of the LpoA N domain. We also determined three 2.0-2.8 Å resolution crystal structures containing four independent full-length LpoA molecules. In contrast to an elongated model previously suggested for LpoA, each LpoA formed a U-shaped structure with a different C-domain orientation. This resulted from both N-domain twisting and rotation of the C domain (up to 30°) at the end of the relatively immobile interdomain linker. Moreover, a previously predicted hinge between the lobes of the LpoA C domain exhibited variations of up to 12°. Small-angle X-ray scattering data revealed excellent agreement with a model calculated by normal mode analysis from one of the full-length LpoA molecules but even better agreement with an ensemble of this molecule and two of the partially extended normal mode analysis-predicted models. The different LpoA structures helped explain how an outer membrane-anchored LpoA can either withdraw from or extend toward the inner membrane-bound PBP1A through peptidoglycan gaps and hence regulate the synthesis of peptidoglycan necessary for bacterial viability.

PubMed: 28887305
DOI: 10.1074/jbc.M117.804997

Experimental method

X-RAY DIFFRACTION (1.965 Å)