TY - JOUR
T1 - Proton ATPases in bacteria
T2 - Comparison to Escherichia coli F1F0 as the prototype
AU - Fillingame, Robert H.
AU - Divall, Sara
PY - 1999
Y1 - 1999
N2 - The F1F0 ATP synthase complex of Escherichia coli functions reversibly in coupling proton translocation to ATP synthesis or hydrolysis. The structural organization and subunit composition corresponds to that seen in many other bacteria, i.e. a membrane extrinsic F1 sector with five subunits in an α3β3γδε stoichiometry, and a membrane-traversing F0 sector with three subunits in an a1b2c12 stoichiometry. The structure of much of the F1 sector is known from a X-ray diffraction model. During function, the γ subunit is known to rotate within a hexameric ring of alternating α and β subunits to promote sequential substrate binding and product release from catalytic sites on the three β subunits. Proton transport through F0 must be coupled to this rotation. Subunit c folds in the membrane as a hairpin to two a helices to generate the proton-binding site in F0. Its structure was determined by NMR, and the structure of the c oligomer was deduced by cross-linking experiments and molecular mechanics calculations. The implications of the oligomeric structure of subunit c will be considered and related to the H+/ATP pumping ratio, P/O ratios and the cation-binding site in other types of F0. The possible limits of the structure in changing the ion-binding specificity, stoichiometry and routes of proton entrance/exit to the binding site will be considered.
AB - The F1F0 ATP synthase complex of Escherichia coli functions reversibly in coupling proton translocation to ATP synthesis or hydrolysis. The structural organization and subunit composition corresponds to that seen in many other bacteria, i.e. a membrane extrinsic F1 sector with five subunits in an α3β3γδε stoichiometry, and a membrane-traversing F0 sector with three subunits in an a1b2c12 stoichiometry. The structure of much of the F1 sector is known from a X-ray diffraction model. During function, the γ subunit is known to rotate within a hexameric ring of alternating α and β subunits to promote sequential substrate binding and product release from catalytic sites on the three β subunits. Proton transport through F0 must be coupled to this rotation. Subunit c folds in the membrane as a hairpin to two a helices to generate the proton-binding site in F0. Its structure was determined by NMR, and the structure of the c oligomer was deduced by cross-linking experiments and molecular mechanics calculations. The implications of the oligomeric structure of subunit c will be considered and related to the H+/ATP pumping ratio, P/O ratios and the cation-binding site in other types of F0. The possible limits of the structure in changing the ion-binding specificity, stoichiometry and routes of proton entrance/exit to the binding site will be considered.
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M3 - Review article
C2 - 10207922
AN - SCOPUS:0032603315
SN - 1528-2511
VL - 221
SP - 218
EP - 229
JO - Novartis Foundation Symposium
JF - Novartis Foundation Symposium
ER -