The maltose ABC transporter: Action of membrane lipids on the transporter stability, coupling and ATPase activity
Huan Bao, Kush Dalal, Victor Wang, Isabelle Rouiller, Franck Duong
Biochimica et Biophysica Acta (BBA) - Lipids and Lipid Metabolism | ELSEVIER SCIENCE BV | Published : 2013
The coupling between ATP hydrolysis and substrate transport remains a key question in the understanding of ABC-mediated transport. We show using the MalFGK2 complex reconstituted into nanodiscs, that membrane lipids participate directly to the coupling reaction by stabilizing the transporter in a low energy conformation. When surrounded by short acyl chain phospholipids, the transporter is unstable and hydrolyzes large amounts of ATP without inducing maltose. The presence of long acyl chain phospholipids stabilizes the conformational dynamics of the transporter, reduces its ATPase activity and restores dependence on maltose. Membrane lipids therefore play an essential allosteric function, th..View full abstract
Awarded by CIHR
H.B. is recipient of a FYF fellowship from the University of British Columbia. This work was supported by the CIHR MOP-86693 (to I.R) and the NSERC and the CFI (to F.D.). I.R. is a CIHR New Investigator. F.D. is a Canada Research Chair Tier II.