7AHE

OpuA inhibited inward facing

Summary for 7AHE

• Entry DOI: 10.2210/pdb7ahe/pdb
• EMDB information: 11782 11783 11784 11785 11786
• Descriptor: ABC transporter permease subunit, ABC-type proline/glycine betaine transport system ATPase component, (2R,3R,3aS,5R,7aR,9R,10R,10aS,12R,14aR)-2,9-bis(6-amino-9H-purin-9-yl)octahydro-2H,7H-difuro[3,2-d:3',2'-j][1,3,7,9,2,8 ]tetraoxadiphosphacyclododecine-3,5,10,12-tetrol 5,12-dioxide (3 entities in total)
• Functional Keywords: osmoregulation, abc-transporter, glycine betaine uptake system, membrane protein, cyclic-di-amp
• Biological source: Lactococcus lactis subsp. lactis; More
• Total number of polymer chains: 4
• Total formula weight: 219101.40

Authors

Sikkema, H.R.,Rheinberger, J.,Paulino, C.,Poolman, B. (deposition date: 2020-09-24, release date: 2020-11-25, Last modification date: 2024-05-01)

Primary citation

Sikkema, H.R.,van den Noort, M.,Rheinberger, J.,de Boer, M.,Krepel, S.T.,Schuurman-Wolters, G.K.,Paulino, C.,Poolman, B.
Gating by ionic strength and safety check by cyclic-di-AMP in the ABC transporter OpuA.
Sci Adv, 6:-, 2020

PubMed Abstract: (Micro)organisms are exposed to fluctuating environmental conditions, and adaptation to stress is essential for survival. Increased osmolality (hypertonicity) causes outflow of water and loss of turgor and is dangerous if the cell is not capable of rapidly restoring its volume. The osmoregulatory adenosine triphosphate-binding cassette transporter OpuA restores the cell volume by accumulating large amounts of compatible solute. OpuA is gated by ionic strength and inhibited by the second messenger cyclic-di-AMP, a molecule recently shown to affect many cellular processes. Despite the master regulatory role of cyclic-di-AMP, structural and functional insights into how the second messenger regulates (transport) proteins on the molecular level are lacking. Here, we present high-resolution cryo-electron microscopy structures of OpuA and in vitro activity assays that show how the osmoregulator OpuA is activated by high ionic strength and how cyclic-di-AMP acts as a backstop to prevent unbridled uptake of compatible solutes.

PubMed: 33208376
DOI: 10.1126/sciadv.abd7697

Experimental method

ELECTRON MICROSCOPY (4.1 Å)