Open AccessCoupled ATPase-adenylate kinase activity in ABC transporters
Author(s) -
Hundeep Kaur,
Andrea Lakatos-Karoly,
Ramona Vogel,
Andrea Noll,
Robert Tampé,
Clemens Glaubitz
Publication year - 2016
Publication title -
nature communications
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.559
H-Index - 365
ISSN - 2041-1723
DOI - 10.1038/ncomms13864
Subject(s) - atp binding cassette transporter , adenylate kinase , biochemistry , atpase , atp hydrolysis , nucleotide , cyclic nucleotide binding domain , walker motifs , adenosine triphosphate , biology , chemistry , microbiology and biotechnology , enzyme , transporter , gene
ATP-binding cassette (ABC) transporters, a superfamily of integral membrane proteins, catalyse the translocation of substrates across the cellular membrane by ATP hydrolysis. Here we demonstrate by nucleotide turnover and binding studies based on 31 P solid-state NMR spectroscopy that the ABC exporter and lipid A flippase MsbA can couple ATP hydrolysis to an adenylate kinase activity, where ADP is converted into AMP and ATP. Single-point mutations reveal that both ATPase and adenylate kinase mechanisms are associated with the same conserved motifs of the nucleotide-binding domain. Based on these results, we propose a model for the coupled ATPase-adenylate kinase mechanism, involving the canonical and an additional nucleotide-binding site. We extend these findings to other prokaryotic ABC exporters, namely LmrA and TmrAB, suggesting that the coupled activities are a general feature of ABC exporters.