Domain in bacteria

Bakal, C.J. Davies, J.E. (2000) No longer an exclusive club eukaryotic signaling domains in bacteria. Trends Cell Biol. 10, 32-38. 

The disposition of the different metal centres of bovine heart CcOx is represented in Figure 14.9. The dimetallic CuA site receives electrons directly from cytochrome c, and is located in a globular domain of subunit II, which protrudes into the intermembrane space (the periplasmic space in bacteria). This centre, which was widely believed to be mononuclear is a dicopper site (Figure 14.10) in which the coppers are bridged by two cysteine sul-furs each copper in addition has two other protein ligands. In the one electron-reduced form,... 

EFTsNT A UBA-like domain with a clear role outside of ubiquitin binding is found at the N-terminus of EF-Ts proteins. The relationship of this region to genuine UBA domains is well established as there is a structure of full-length EF-Ts available [67]. Nevertheless, this domain is widespread in bacteria and archaea, which obviously lack a proper ubiquitin system. The physiological role of the EFTsNT domain is rather in the binding to the elongation factor EF-Tu, which has no resemblance to ubiquitin. 

Fusion protein pull-down assays involve the overexpression of bait and/or fusion proteins in bacteria. Often, the expressed fusion proteins are localized in occlusion bodies and not readily soluble under nondenaturing conditions. The expressed proteins can be extracted using urea, sonication, sodium dodecyl sulfate (SDS), or a combination of all the three. The net result is the denaturation of the recombinant protein and it may need to be refolded if the interaction domain is conformationally dependent. A major advantage of the pull-down assay is that high concentrations of proteins can be easily generated thus favoring protein association for a reversible equilibrium between two proteins. 

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