Download MendeleyStructural Studies of Potassium Transport Protein KtrA Regulator of Conductance of K+ (RCK) C Domain in Complex with Cyclic Diadenosine Monophosphate (c-di-AMP)
Kim, H., Youn, S.J., Kim, S.O., Ko, J., Lee, J.O., Choi, B.S.(2015) J Biol Chem 290: 16393-16402
- PubMed: 25957408
- DOI: https://doi.org/10.1074/jbc.M115.641340
- Primary Citation of Related Structures:
4XTT - 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.
Organizational Affiliation:
From the Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 305-701, Korea.
