Bacterial Electron Transfer Chains Primed by Proteomics

Abstract

Electron transport phosphorylation is the central mechanism for most prokaryotic species to harvest energy released in the respiration of their substrates as ATP. Microorganisms have evolved incredible variations on this principle, most of these we perhaps do not know, considering that only a fraction of the microbial richness is known. Besides these variations, microbial species may show substantial versatility in using respiratory systems. In connection herewith, regulatory mechanisms control the expression of these respiratory enzyme systems and their assembly at the translational and posttranslational levels, to optimally accommodate changes in the supply of their energy substrates. Here, we present an overview of methods and techniques from the field of proteomics to explore bacterial electron transfer chains and their regulation at levels ranging from the whole organism down to the Ångstrom scales of protein structures. From the survey of the literature on this subject, it is concluded that proteomics, indeed, has substantially contributed to our comprehending of bacterial respiratory mechanisms, often in elegant combinations with genetic and biochemical approaches. However, we also note that advanced proteomics offers a wealth of opportunities, which have not been exploited at all, or at best underexploited in hypothesis-driving and hypothesis-driven research on bacterial bioenergetics. Examples obtained from the related area of mitochondrial oxidative phosphorylation research, where the application of advanced proteomics is more common, may illustrate these opportunities.

Opportunities for Overcoming Mycobacterium tuberculosis Drug Resistance: Emerging Mycobacterial Targets and Host-Directed Therapy

“…The energy of the electrochemical proton gradient then drives the final step, i.e., synthesis of ATP by ATP synthase. As Mtb is an obligate aerobic pathogen, the process of oxidative phosphorylation is essential for mycobacterial survival and growth [46,47]. Due to its essential character, the oxidative phosphorylation makes up an interesting source of novel targets for anti-TB drug discovery (Table 1).…”

Systems Microbiology and Engineering of Aerobic-Anaerobic Ammonium Oxidation

“…Examination of metabolic regulation in microorganisms and communities is challenging since this involves a multitude of transcriptional (i.e., mRNA level), translational (proteins), post-translational (enzyme activation), and metabolite-flux-based regulatory mechanisms [122][123][124][125][126][127][128][129][130] . Regulatory controls underlying the biochemical performance of PN/A are mostly unexplored.…”

Metabolic engineering and bio-electrochemical synthesis in Pseudomonas putida KT2440 for the production of p-hydroxybenzoate and 2-ketogluconate

“…If the key components of ETC were to be correctly assembled and located in the specific location, they would forming a complete ETC, which can then be expected to endow electro-activity in the new host. From literature, many ETC gene targets have been effectively obtained from comparative 'omics technologies such as genomics, transcriptomics and proteomics (Beliaev et al, 2002a;Beliaev et al, 2002b;Holmes et al, 2006;Wessels et al, 2016), further demonstrated by mutagenesis (or gene dele tion) and overexpression complementation experiments (Bretschger et al, 2008;Jin et al, 2013), and finally characterized specific function during electron transfer via genetics and biochemistry analysis (Yuan et al, 2011), X-ray crystallography (structure) (Malvankar et al, 2015), NMR spectroscopy (internal motions and interactions, thermodynamic characterization) (Dantas et al, 2015). Electron transfer chain design could start from the selection of key ETC proteins including extracellular electron transfer chain (involving electron transfer with the electrode), 'linker proteins' supporting the ETC event in periplasm, and proteins involved in the respiratory chain.…”