A dinâmica da haste de estatores rotativos das ATPases

quarta-feira, fevereiro 22, 2012


The dynamic stator stalk of rotary ATPases

Alastair G. Stewart, Lawrence K. Lee, Mhairi Donohoe, Jessica J. Chaston & Daniela Stock

Affiliations Contributions Corresponding author

Nature Communications 3, Article number: 687 doi:10.1038/ncomms1693

Received 26 October 2011 Accepted 19 January 2012 Published 21 February 2012


Rotary ATPases couple ATP hydrolysis/synthesis with proton translocation across biological membranes and so are central components of the biological energy conversion machinery. Their peripheral stalks are essential components that counteract torque generated by rotation of the central stalk during ATP synthesis or hydrolysis. Here we present a 2.25-Å resolution crystal structure of the peripheral stalk from Thermus thermophilus A-type ATPase/synthase. We identify bending and twisting motions inherent within the structure that accommodate and complement a radial wobbling of the ATPase headgroup as it progresses through its catalytic cycles, while still retaining azimuthal stiffness necessary to counteract rotation of the central stalk. The conformational freedom of the peripheral stalk is dictated by its unusual right-handed coiled-coil architecture, which is in principle conserved across all rotary ATPases. In context of the intact enzyme, the dynamics of the peripheral stalks provides a potential mechanism for cooperativity between distant parts of rotary ATPases.

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Subject terms: Biological sciences Biochemistry Biophysics