High affinity nucleotide-binding mutant of the ε subunit of thermophilic F1-ATPase

Specific ATP binding to the epsilon subunit of thermophilic F-1-ATPase has been utilized for the biosensors of ATP in vivo. I report here that the epsilon subunit containing R103A/R115A mutations can bind ATP with a dissociation constant at 52 nM, which is two orders of magnitude higher affinity than the wild type. The mutant retained specificity for ATP; ADP and GTP bound to the mutant with dissociation constants 16 and 53 mu M, respectively. Thus, the mutant would be a good platform for various types of nucleotide biosensor with appropriate modifications. (C) 2015 Elsevier Inc. All rights reserved.