4XTT

Structural Studies of Potassium Transport Protein KtrA Regulator of Conductance of K+ (RCK) C domain in Complex with Cyclic Diadenosine Monophosphate (c-di-AMP)

Summary for 4XTT

• Entry DOI: 10.2210/pdb4xtt/pdb
• Descriptor: Putative potassium transport protein, (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: potassium, transporter, ktra, c-di-amp, transport protein
• Biological source: Staphylococcus aureus 08BA02176
• Total number of polymer chains: 2
• Total formula weight: 19632.09

Authors

Kim, H.,Youn, S.J.,Kim, S.O.,Ko, J.,Lee, J.O.,Choi, B.S. (deposition date: 2015-01-24, release date: 2015-05-20, Last modification date: 2023-11-08)

Primary citation

Kim, H.,Youn, S.J.,Kim, S.O.,Ko, J.,Lee, J.O.,Choi, B.S.
Structural Studies of Potassium Transport Protein KtrA Regulator of Conductance of K+ (RCK) C Domain in Complex with Cyclic Diadenosine Monophosphate (c-di-AMP)
J.Biol.Chem., 290:16393-16402, 2015

PubMed Abstract: Although it was only recently identified as a second messenger, c-di-AMP was found to have fundamental importance in numerous bacterial functions such as ion transport. The potassium transporter protein, KtrA, was identified as a c-di-AMP receptor. However, the co-crystallization of c-di-AMP with the protein has not been studied. Here, we determined the crystal structure of the KtrA RCK_C domain in complex with c-di-AMP. The c-di-AMP nucleotide, which adopts a U-shaped conformation, is bound at the dimer interface of RCK_C close to helices α3 and α4. c-di-AMP interacts with KtrA RCK_C mainly by forming hydrogen bonds and hydrophobic interactions. c-di-AMP binding induces the contraction of the dimer, bringing the two monomers of KtrA RCK_C into close proximity. The KtrA RCK_C was able to interact with only c-di-AMP, but not with c-di-GMP, 3',3-cGAMP, ATP, and ADP. The structure of the KtrA RCK_C domain and c-di-AMP complex would expand our understanding about the mechanism of inactivation in Ktr transporters governed by c-di-AMP.

PubMed: 25957408
DOI: 10.1074/jbc.M115.641340

Experimental method

X-RAY DIFFRACTION (2.708 Å)