6s2u

Structure of the catalytic domain of T. thermophilus Rel in complex with AMP and ppGpp

spinqualitylabelsall models 6s2u, resolution 2.95Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 6s2u is a 1 chain structure with sequence from Thermus thermophilus. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 2.95Å Ligands: AMP, GN3, MG, MN, TMO Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function Q5SHL3_THET8 In eubacteria ppGpp (guanosine 3'-diphosphate 5'-diphosphate) is a mediator of the stringent response that coordinates a variety of cellular activities in response to changes in nutritional abundance.[RuleBase:RU003847] Publication Abstract from PubMed Bifunctional Rel stringent factors, the most abundant class of RelA/SpoT homologs, are ribosome-associated enzymes that transfer a pyrophosphate from ATP onto the 3' of guanosine tri-/diphosphate (GTP/GDP) to synthesize the bacterial alarmone (p)ppGpp, and also catalyze the 3' pyrophosphate hydrolysis to degrade it. The regulation of the opposing activities of Rel enzymes is a complex allosteric mechanism that remains an active research topic despite decades of research. We show that a guanine-nucleotide-switch mechanism controls catalysis by Thermus thermophilus Rel (RelTt). The binding of GDP/ATP opens the N-terminal catalytic domains (NTD) of RelTt (RelTt(NTD)) by stretching apart the two catalytic domains. This activates the synthetase domain and allosterically blocks hydrolysis. Conversely, binding of ppGpp to the hydrolase domain closes the NTD, burying the synthetase active site and precluding the binding of synthesis precursors. This allosteric mechanism is an activity switch that safeguards against futile cycles of alarmone synthesis and degradation. A nucleotide-switch mechanism mediates opposing catalytic activities of Rel enzymes.,Tamman H, Van Nerom K, Takada H, Vandenberk N, Scholl D, Polikanov Y, Hofkens J, Talavera A, Hauryliuk V, Hendrix J, Garcia-Pino A Nat Chem Biol. 2020 Aug;16(8):834-840. doi: 10.1038/s41589-020-0520-2. Epub 2020 , May 11. PMID:32393900 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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