Download MendeleyStructural Basis of Pullulanase Membrane Binding and Secretion Revealed by X-Ray Crystallography, Molecular Dynamics and Biochemical Analysis
East, A., Mechaly, A.E., Huysmans, G.H.M., Bernarde, C., Tello-Manigne, D., Nadeau, N., Pugsley, A.P., Buschiazzo, A., Alzari, P.M., Bond, P.J., Francetic, O.(2016) Structure 24: 92
- PubMed: 26688215 Search on PubMed
- DOI: https://doi.org/10.1016/j.str.2015.10.023
- Primary Citation Related Structures:
2YOC - PubMed Abstract:
The Klebsiella lipoprotein pullulanase (PulA) is exported to the periplasm, triacylated, and anchored via lipids in the inner membrane (IM) prior to its transport to the bacterial surface through a type II secretion system (T2SS). X-Ray crystallography and atomistic molecular dynamics (MD) simulations of PulA in a 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphoethanolamine (POPE) model membrane provided an unprecedented molecular view of an N-terminal unstructured tether and the IM lipoprotein retention signal, and revealed novel interactions with the IM via N-terminal immunoglobulin-like domains in PulA. An efficiently secreted nonacylated variant (PulANA) showed similar peripheral membrane association during MD simulations, consistent with the binding of purified PulANA to liposomes. Remarkably, combined X-ray, MD, and functional studies identified a novel subdomain, Ins, inserted in the α-amylase domain, which is required for PulA secretion. Available data support a model in which PulA binding to the IM promotes interactions with the T2SS, possibly via the Ins subdomain.
- Department of Chemistry, Centre for Molecular Informatics, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK.
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