7WEM

Solid-state NMR Structure of TFo c-Subunit Ring

Summary for 7WEM

• Entry DOI: 10.2210/pdb7wem/pdb
• Descriptor: ATP synthase subunit c (1 entity in total)
• Functional Keywords: decamer helices ring in membrane atp synthase rotor, proton transport
• Biological source: Bacillus sp. PS3
• Total number of polymer chains: 10
• Total formula weight: 73888.50

Authors

Akutsu, H.,Todokoro, Y.,Kang, S.-J.,Suzuki, T.,Yoshida, M.,Ikegami, T.,Fujiwara, T. (deposition date: 2021-12-23, release date: 2022-08-10, Last modification date: 2024-05-15)

Primary citation

Todokoro, Y.,Kang, S.J.,Suzuki, T.,Ikegami, T.,Kainosho, M.,Yoshida, M.,Fujiwara, T.,Akutsu, H.
Chemical Conformation of the Essential Glutamate Site of the c -Ring within Thermophilic Bacillus F o F 1 -ATP Synthase Determined by Solid-State NMR Based on its Isolated c -Ring Structure.
J.Am.Chem.Soc., 144:14132-14139, 2022

PubMed Abstract: Proton translocation through the membrane-embedded F component of F-type ATP synthase (FF) is facilitated by the rotation of the F -subunit ring (-ring), carrying protons at essential acidic amino acid residues. Cryo-electron microscopy (Cryo-EM) structures of FF suggest a unique proton translocation mechanism. To elucidate it based on the chemical conformation of the essential acidic residues of the -ring in FF, we determined the structure of the isolated thermophilic F (tF) -ring, consisting of 10 subunits, in membranes by solid-state NMR. This structure contains a distinct proton-locking conformation, wherein Asn23 (N23) CO and Glu56 (E56) COH form a hydrogen bond in a closed form. We introduced stereo-array-isotope-labeled (SAIL) Glu and Asn into the tF-ring to clarify the chemical conformation of these residues in tFF-ATP synthase (tFF). Two well-separated C signals could be detected for N23 and E56 in a 505 kDa membrane protein complex, respectively, thereby suggesting the presence of two distinct chemical conformations. Based on the signal intensity and structure of the tF-ring and tFF, six pairs of N23 and E56 surrounded by membrane lipids take the closed form, whereas the other four in the - interface employ the deprotonated open form at a proportion of 87%. This indicates that the - interface is highly hydrophilic. The p values of the four E56 residues in the - interface were estimated from the N23 signal intensity in the open and closed forms and distribution of polar residues around each E56. The results favor a rotation of the -ring for ATP synthesis.

PubMed: 35905443
DOI: 10.1021/jacs.2c03580

Experimental method

SOLID-STATE NMR