The NMR solution structure of Mycobacterium tuberculosis F‐ATP synthase subunit ε provides new insight into energy coupling inside the rotary engine. (6th February 2018)

• Record Type: Journal Article
• Authors: Joon, Shin; Ragunathan, Priya; Sundararaman, Lavanya; Nartey, Wilson; Kundu, Subhashri; Manimekalai, Malathy S. S.; Bogdanović, Nebojša; Dick, Thomas; Grüber, Gerhard
• Is Part Of: FEBS journal. Volume 285:Number 6(2018)
• Page Start: 1111
• Page End: 1128
• Publication Date: 2018-02-06
• Subjects: bioenergetics -- F‐ATP synthase -- membrane enzyme -- Mycobacterium -- subunit ε -- tuberculosis; Biochemistry -- Periodicals; Molecular biology -- Periodicals; Pathology, Molecular -- Periodicals; 572
• DOI: 10.1111/febs.14392
• Languages: English
• ISSNs: 1742-464X

Abstract

Abstract : Mycobacterium tuberculosis (Mt) F1 F0 ATP synthase (α3 :β3 :γ:δ:ε: a : b : b′ : c 9 ) is essential for the viability of growing and nongrowing persister cells of the pathogen. Here, we present the first NMR solution structure of Mt ε, revealing an N‐terminal β‐barrel domain (NTD) and a C‐terminal domain (CTD) composed of a helix‐loop‐helix with helix 1 and ‐2 being shorter compared to their counterparts in other bacteria. The C‐terminal amino acids are oriented toward the NTD, forming a domain‐domain interface between the NTD and CTD. The Mt ε structure provides a novel mechanistic model of coupling c ‐ring‐ and ε rotation via a patch of hydrophobic residues in the NTD and residues of the CTD to the bottom of the catalytic α3 β3 ‐headpiece. To test our model, genome site‐directed mutagenesis was employed to introduce amino acid changes in these two parts of the epsilon subunit. Inverted vesicle assays show that these mutations caused an increase in ATP hydrolysis activity and a reduction in ATP synthesis. The structural and enzymatic data are discussed in light of the transition mechanism of a compact and extended state of Mt ε, which provides the inhibitory effects of this coupling subunit inside the rotary engine. Finally, the employment of these data with molecular docking shed light into the second binding site of the drug Bedaquiline. Database: Structural data are available in the PDB under the accession number5YIO . Abstract : The F1 FO ATP synthase has been shown to be essential for growth in Mycobacterium tuberculosis . Energy coupling between the ion‐translocating FO ‐part and the catalytic α3:β3 section of F1 has to be coupled via the rotary subunits γ and ε. Here, the NMR solution structure of M. tuberculosis subunit ε has been determined and new insight into energy coupling is provided.