Enterococcus faecalis is often coisolated with Pseudomonas aeruginosa in polymicrobial biofilm-associated infections of wounds and the urinary tract. As a defense strategy, the host innately restricts iron availability at infection sites. Despite their coprevalence, the polymicrobial interactions of these two species in biofilms and under iron-restricted conditions remain unexplored.
View Article and Find Full Text PDFThe dynamic interaction of the N- and C-terminal domains of mycobacterial F-ATP synthase subunit ε is proposed to contribute to efficient coupling of H-translocation and ATP synthesis. Here, we investigate crosstalk between both subunit ε domains by introducing chromosomal atpC missense mutations in the C-terminal helix 2 of ε predicted to disrupt inter domain and subunit ε-α crosstalk and therefore coupling. The ε mutant εR105A,R111A,R113A,R115A (ε) showed decreased intracellular ATP, slower growth rates and lower molar growth yields on non-fermentable carbon sources.
View Article and Find Full Text PDFThe FF -ATP (F-ATP) synthase is essential for growth of , the causative agent of tuberculosis (TB). In addition to their synthase function most F-ATP synthases possess an ATP-hydrolase activity, which is coupled to proton-pumping activity. However, the mycobacterial enzyme lacks this reverse activity, but the reason for this deficiency is unclear.
View Article and Find Full Text PDFThe angular velocities of ATPase-dependent power strokes as a function of the rotational position for the A-type molecular motor ABDF, from the Methanosarcina mazei Gö1 A-ATP synthase, and the thermophilic motor αβγ, from Geobacillus stearothermophilus (formerly known as Bacillus PS3) F-ATP synthase, are resolved at 5 μs resolution for the first time. Unexpectedly, the angular velocity profile of the A-type was closely similar in the angular positions of accelerations and decelerations to the profiles of the evolutionarily distant F-type motors of thermophilic and mesophilic origins, and they differ only in the magnitude of their velocities. M.
View Article and Find Full Text PDFAntimicrob Agents Chemother
November 2016
The tuberculosis drug bedaquiline inhibits mycobacterial F-ATP synthase by binding to its c subunit. Using the purified ε subunit of the synthase and spectroscopy, we previously demonstrated that the drug interacts with this protein near its unique tryptophan residue. Here, we show that replacement of ε's tryptophan with alanine resulted in bedaquiline hypersusceptibility of the bacteria.
View Article and Find Full Text PDFThe F1 FO -ATP synthase is one of the enzymes that is essential to meet the energy requirement of both the proliferating aerobic and hypoxic dormant stages of the life cycle of mycobacteria. Most F-ATP synthases consume ATP in the α3 :β3 headpiece to drive the γ subunit, which couples ATP cleavage with proton pumping in the c ring of FO via the bottom of the γ subunit. ATPase-driven H(+) pumping is latent in mycobacteria.
View Article and Find Full Text PDFThe DNA-translocator ATPase PilF of Thermus thermophilus HB27 is a hexamer built by six identical subunits. Despite the presence of a conserved zinc-binding site in every subunit, only one zinc atom per hexamer was found. Re-examination of the zinc content of PilF purified from cells grown in complex media with different lots of yeast extract revealed six zinc atoms per hexamer.
View Article and Find Full Text PDFTuberculosis, caused by the strain Mycobacterium tuberculosis, is in focus of interest due to the emergence of multi- and extensive drug-resistant TB strains. The F(1)F(O) ATP synthase is one of the essential enzymes in energy requirement of both proliferating aerobic and hypoxic dormant stage of mycobacterium life cycle, and therefore a potential TB drug target. Subunit γ of F-ATP synthases plays an important role in coupling and catalysis via conformational transitions of its N- and C-termini as well as the bottom segment of the globular domain of γ, which is in close proximity to the rotating and ion-pumping c-ring.
View Article and Find Full Text PDFAntimicrob Agents Chemother
January 2013
The subunit ε of bacterial F(1)F(O) ATP synthases plays an important regulatory role in coupling and catalysis via conformational transitions of its C-terminal domain. Here we present the first low-resolution solution structure of ε of Mycobacterium tuberculosis (Mtε) F(1)F(O) ATP synthase and the nuclear magnetic resonance (NMR) structure of its C-terminal segment (Mtε(103-120)). Mtε is significantly shorter (61.
View Article and Find Full Text PDFBackground: Dengue virus surface proteins, envelope (E) and pre-membrane (prM), undergo rearrangement during the maturation process at acidic condition.
Results: prM-stem region binds tighter to both E protein and lipid membrane when environment becomes acidic.
Conclusion: At acidic condition, E proteins are attracted to the membrane-associated prM-stem.
Thermus thermophilus is a model strain to unravel the molecular basis of horizontal gene transfer in hot environments. Previous genetic studies led to the identification of a macromolecular transport machinery mediating DNA uptake in an energy-dependent manner. Here, we have addressed how the transporter is energized.
View Article and Find Full Text PDFThe mutants P235A and F236A have been generated and their crystal structure was determined to resolutions of 2.38 and 2.35 A, respectively, in order to understand the residues involved in the formation of the novel arched P-loop of subunit A of the A-ATP synthase from Pyrococcus horikoshii OT3.
View Article and Find Full Text PDFSubunit b, the peripheral stalk of bacterial F(1)F(o) ATP synthases, is composed of a membrane-spanning and a soluble part. The soluble part is divided into tether, dimerization, and delta-binding domains. The first solution structure of b30-82, including the tether region and part of the dimerization domain, has been solved by nuclear magnetic resonance, revealing an alpha-helix between residues 39 and 72.
View Article and Find Full Text PDFA series of truncated forms of subunit H were generated to establish the domain features of that protein. Circular dichroism analysis demonstrated that H is divided at least into a C-terminal coiled-coil domain within residues 54-104, and an N-terminal domain formed by adjacent alpha-helices. With a cysteine at the C-terminus of each of the truncated proteins (H(1-47), H(1-54), H(1-59), H(1-61), H(1-67), H(1-69), H(1-71), H(1-78), H(1-80), H(1-91), and H(47-105)), the residues involved in formation of the coiled-coil interface were determined.
View Article and Find Full Text PDFThe boomerang-like H subunit of A(1)A(0) ATP synthase forms one of the peripheral stalks connecting the A(1) and A(0) sections. Structural analyses of the N-terminal part (H1-47) of subunit H of the A(1)A(0) ATP synthase from Methanocaldococcus jannaschii have been performed by NMR spectroscopy. Our initial NMR structural calculations for H1-47 indicate that amino acid residues 7-44 fold into a single alpha-helical structure.
View Article and Find Full Text PDFThe A1AO adenosine triphosphate (ATP) synthase from archaea uses the ion gradients generated across the membrane sector (AO) to synthesize ATP in the A3B3 domain of the A1 sector. The energy coupling between the two active domains occurs via the so-called stalk part(s), to which the 12 kDa subunit F does belong. Here, we present the solution structure of the F subunit of the A1AO ATP synthase from Methanosarcina mazei Gö1.
View Article and Find Full Text PDFEnergy coupling between the A(1 )ATPase of archaea type A(1)A(O) ATP synthase and its integral membrane sub-complex A(O) occurs via the stalk part, formed by the subunits C, D and F. To provide a molecular basis of the energy coupling, we performed NMR studies. Here, we report the assignment of the subunit F.
View Article and Find Full Text PDFThe H subunit of the A1AO ATP synthase is a component of one of the peripheral stalks connecting the A1 and AO domain. Subunit H of the Methanocaldococcus jannaschii A1AO ATP synthase was analyzed by small-angle X-ray scattering (SAXS) in order to determine the first low-resolution structure of this molecule in solution. Independent to the concentration used, the protein is dimeric and has a boomerang-like shape, divided into two arms of 12.
View Article and Find Full Text PDFThe first low-resolution shape of subunit F of the A(1)A(O) ATP synthase from the archaeon Methanosarcina mazei Gö1 in solution was determined by small angle X-ray scattering. Independent to the concentration used, the protein is monomeric and has an elongated shape, divided in a main globular part with a length of about 4.5 nm, and a hook-like domain of about 3.
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