Regulation and action of the bacterial enhancer-binding protein AAA+ domains.
Bacterial EBPs (enhancer-binding proteins) play crucial roles in regulating cellular responses to environmental changes, in part by providing efficient control over sigma(54)-dependent gene transcription. The AAA+ (ATPase associated with various cellular activites) domain of the EBPs, when assembled into a ring, uses energy from ATP binding, hydrolysis and product release to remodel the sigma(54)-RNAP (RNA polymerase) holoenzyme so that it can transition from closed to open form at promoter DNA. The assembly, and hence activity, of these ATPases are regulated by many different signal transduction mechanisms. Recent advances in solution scattering techniques, when combined with high-resolution structures and biochemical data, have enabled us to obtain mechanistic insights into the regulation and action of a subset of these sigma(54) activators: those whose assembly into ring form is controlled by two-component signal transduction. We review (i) experimental considerations of applying the SAXS (small-angle X-ray scattering)/WAXS (wide-angle X-ray scattering) technique, (ii) distinct regulation mechanisms of the AAA+ domains of three EBPs by similar two-component signal transduction receiver domains, and (iii) major conformational changes and correlated sigma(54)-binding activity of an isolated EBP AAA+ domain in the ATP hydrolysis cycle.
Chen
Baoyu
B
Integrative Biosciences Graduate Degree Program - Chemical Biology, The Pennsylvania State University, University Park, PA 16802, USA.
Sysoeva
Tatyana A
TA
Chowdhury
Saikat
S
Nixon
B Tracy
BT
D001426:Bacterial Proteins / Q000737:chemistry* / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000737:chemistry* / Q000378:metabolism*; D008666:Metalloendopeptidases / Q000737:chemistry*; D011487:Protein Conformation; D017434:Protein Structure, Tertiary; D053838:Scattering, Small Angle; D015398:Signal Transduction; D014961:X-Ray Diffraction
D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; D008666:Metalloendopeptidases; C114583:m-AAA proteases