Database of articles cited by EMDB/PDB/SASBDB data

Keywords
Structure methods	All X-ray diffraction NMR electron microscopy small angle scattering neutron diffraction fiber diffraction powder diffraction infrared spectroscopy EPR fluorescence transfer theoretical model Hybrid
Author
Journal
IF	>30 >20 >10 >5 all

Title	The allosteric control mechanism of bacterial glycogen biosynthesis disclosed by cryoEM.
Journal, issue, pages	Curr Res Struct Biol, Vol. 2, Page 89-8103, Year 2020
Publish date	May 1, 2020
Authors	Javier O Cifuente / Natalia Comino / Cecilia D'Angelo / Alberto Marina / David Gil-Carton / David Albesa-Jové / Marcelo E Guerin /
PubMed Abstract	Glycogen and starch are the major carbon and energy reserve polysaccharides in nature, providing living organisms with a survival advantage. The evolution of the enzymatic machinery responsible for ...Glycogen and starch are the major carbon and energy reserve polysaccharides in nature, providing living organisms with a survival advantage. The evolution of the enzymatic machinery responsible for the biosynthesis and degradation of such polysaccharides, led the development of mechanisms to control the assembly and disassembly rate, to store and recover glucose according to cell energy demands. The tetrameric enzyme ADP-glucose pyrophosphorylase (AGPase) catalyzes and regulates the initial step in the biosynthesis of both α-polyglucans. AGPase displays cooperativity and allosteric regulation by sensing metabolites from the cell energy flux. The understanding of the allosteric signal transduction mechanisms in AGPase arises as a long-standing challenge. In this work, we disclose the cryoEM structures of the paradigmatic homotetrameric AGPase from (AGPase), in complex with either positive or negative physiological allosteric regulators, fructose-1,6-bisphosphate (FBP) and AMP respectively, both at 3.0 Å resolution. Strikingly, the structures reveal that FBP binds deeply into the allosteric cleft and overlaps the AMP site. As a consequence, FBP promotes a concerted conformational switch of a regulatory loop, RL2, from a "locked" to a "free" state, modulating ATP binding and activating the enzyme. This notion is strongly supported by our complementary biophysical and bioinformatics evidence, and a careful analysis of vast enzyme kinetics data on single-point mutants of AGPase. The cryoEM structures uncover the residue interaction networks (RIN) between the allosteric and the catalytic components of the enzyme, providing unique details on how the signaling information is transmitted across the tetramer, from which cooperativity emerges. Altogether, the conformational states visualized by cryoEM reveal the regulatory mechanism of AGPase, laying the foundations to understand the allosteric control of bacterial glycogen biosynthesis at the molecular level of detail.
External links	Curr Res Struct Biol / PubMed:34235472 / PubMed Central
Methods	EM (single particle)
Resolution	3.2 - 3.4 Å
Structure data	10199 6shj EMDB-10199, PDB-6shj: Escherichia coli AGPase in complex with FBP. Symmetry applied C2 Method: EM (single particle) / Resolution: 3.2 Å 10201 6shn EMDB-10201, PDB-6shn: Escherichia coli AGPase in complex with FBP. Symmetry C1 Method: EM (single particle) / Resolution: 3.3 Å 10203 6shq EMDB-10203, PDB-6shq: Escherichia coli AGPase in complex with AMP. Symmetry C2 Method: EM (single particle) / Resolution: 3.2 Å 10208 6si8 EMDB-10208, PDB-6si8: Escherichia coli AGPase in complex with AMP. Method: EM (single particle) / Resolution: 3.4 Å
Chemicals	ChemComp-FBP: 1,6-di-O-phosphono-beta-D-fructofuranose ChemComp-AMP: ADENOSINE MONOPHOSPHATE / AMP*YM
Source	escherichia coli (E. coli)
Keywords	TRANSFERASE / ADP-glucose pyrophosphorilase Complex with FBP activator / ADP-glucose pyrophosphorilase Complex with AMP inhibitor