4CBK

The c-ring ion binding site of the ATP synthase from Bacillus pseudofirmus OF4 is adapted to alkaliphilic cell physiology

Summary for 4CBK

• Entry DOI: 10.2210/pdb4cbk/pdb
• Related: 4CBJ
• Descriptor: ATP SYNTHASE SUBUNIT C, dodecyl 2-(trimethylammonio)ethyl phosphate, SODIUM ION, ... (5 entities in total)
• Functional Keywords: transferase, f1fo-atp synthase, c-ring rotor, ion binding pocket
• Biological source: BACILLUS PSEUDOFIRMUS OF4
• Cellular location: Cell membrane; Multi-pass membrane protein (Potential): P22483
• Total number of polymer chains: 13
• Total formula weight: 96146.51

Authors

Preiss, L.,Yildiz, O.,Meier, T. (deposition date: 2013-10-14, release date: 2014-04-23, Last modification date: 2024-10-09)

Primary citation

Preiss, L.,Langer, J.D.,Hicks, D.B.,Liu, J.,Yildiz, O.,Krulwich, T.A.,Meier, T.
The C-Ring Ion-Binding Site of the ATP Synthase from Bacillus Pseudofirmus of4 is Adapted to Alkaliphilic Lifestyle.
Mol.Microbiol., 92:973-, 2014

PubMed Abstract: In the c-ring rotor of ATP synthases ions are shuttled across the membrane during ATP synthesis by a unique rotary mechanism. We investigated characteristics of the c-ring from the alkaliphile Bacillus pseudofirmus OF4 with respect to evolutionary adaptations to operate with protons at high environmental pH. The X-ray structures of the wild-type c13 ring at pH 9.0 and a 'neutralophile-like' mutant (P51A) at pH 4.4, at 2.4 and 2.8 Å resolution, respectively, reveal a dependency of the conformation and protonation state of the proton-binding glutamate (E(54) ) on environmental hydrophobicity. Faster labelling kinetics with the inhibitor dicyclohexylcarbodiimide (DCCD) demonstrate a greater flexibility of E(54) in the mutant due to reduced water occupancy within the H(+) binding site. A second 'neutralophile-like' mutant (V21N) shows reduced growth at high pH, which is explained by restricted conformational freedom of the mutant's E(54) carboxylate. The study directly connects subtle structural adaptations of the c-ring ion binding site to in vivo effects of alkaliphile cell physiology.

PubMed: 24707994
DOI: 10.1111/MMI.12605

Experimental method

X-RAY DIFFRACTION (2.42 Å)