Ion mobility-mass spectrometry of a rotary ATPase reveals ATP-induced reduction in conformational flexibility

TY - JOUR

T1 - Ion mobility-mass spectrometry of a rotary ATPase reveals ATP-induced reduction in conformational flexibility

AU - Zhou, Min

AU - Politis, Anargyros

AU - Davies, Roberta B.

AU - Liko, Idlir

AU - Wu, Kuan Jung

AU - Stewart, Alastair G.

AU - Stock, Daniela

AU - Robinson, Carol V.

PY - 2014/3

Y1 - 2014/3

N2 - Rotary ATPases play fundamental roles in energy conversion as their catalytic rotation is associated with interdomain fluctuations and heterogeneity of conformational states. Using ion mobility mass spectrometry we compared the conformational dynamics of the intact ATPase from Thermus thermophilus with those of its membrane and soluble subcomplexes. Our results define regions with enhanced flexibility assigned to distinct subunits within the overall assembly. To provide a structural context for our experimental data we performed molecular dynamics simulations and observed conformational changes of the peripheral stalks that reflect their intrinsic flexibility. By isolating complexes at different phases of cell growth and manipulating nucleotides, metal ions and pH during isolation, we reveal differences that can be related to conformational changes in the Vo complex triggered by ATP binding. Together these results implicate nucleotides in modulating flexibility of the stator components and uncover mechanistic detail that underlies operation and regulation in the context of the holoenzyme.

AB - Rotary ATPases play fundamental roles in energy conversion as their catalytic rotation is associated with interdomain fluctuations and heterogeneity of conformational states. Using ion mobility mass spectrometry we compared the conformational dynamics of the intact ATPase from Thermus thermophilus with those of its membrane and soluble subcomplexes. Our results define regions with enhanced flexibility assigned to distinct subunits within the overall assembly. To provide a structural context for our experimental data we performed molecular dynamics simulations and observed conformational changes of the peripheral stalks that reflect their intrinsic flexibility. By isolating complexes at different phases of cell growth and manipulating nucleotides, metal ions and pH during isolation, we reveal differences that can be related to conformational changes in the Vo complex triggered by ATP binding. Together these results implicate nucleotides in modulating flexibility of the stator components and uncover mechanistic detail that underlies operation and regulation in the context of the holoenzyme.

UR - http://www.scopus.com/inward/record.url?scp=84895079317&partnerID=8YFLogxK

U2 - 10.1038/nchem.1868

DO - 10.1038/nchem.1868

M3 - Article

C2 - 24557135

AN - SCOPUS:84895079317

SN - 1755-4330

VL - 6

SP - 208

EP - 215

JO - Nature Chemistry

JF - Nature Chemistry

IS - 3

ER -