Literature summary for 2.4.2.9 extracted from

Christoffersen, S.; Kadziola, A.; Johansson, E.; Rasmussen, M.; Willemoes, M.; Jensen, K.F.
Structural and kinetic studies of the allosteric transition in Sulfolobus solfataricus uracil phosphoribosyltransferase: Permanent activation by engineering of the C-terminus (2009), J. Mol. Biol., 393, 464-477.

Activating Compound

Activating Compound	Comment	Organism	Structure
GTP	activating allosteric regulation by GTP. The regulatory triphosphate binds at a site in the center of the tetramer changing the quaternary arrangement. The effector contacts Pro94 at the beginning of a long beta-strand in the dimer interface, which extends into a flexible loop over the active site. In the GTP-bound state, two flexible loop residues, Tyr123 and Lys125, bind the diphosphate moiety of PRPP in the neighboring subunit and contribute to catalysis. The C-terminal Gly216 participates in a hydrogen-bond network in the dimer interface that stabilizes the inhibited, but not the activated, state	Saccharolobus solfataricus

Crystallization (Commentary)

Crystallization (Comment)	Organism
two structures of the activated state enzyme in complex with GTP, X-ray diffraction structure determination and analysis at 2.8 A resolution, the first structure which contains PRPP in all active sites, and 2.9 A resolution, for the second structure with PRPP in two sites and the hydrolysis products ribose-5-phosphate and diphosphate in the other sites, respectively, and a third structure of the enzyme in complex with UMP and the allosteric inhibitor CTP	Saccharolobus solfataricus

Crystallization (Comment)

Organism

two structures of the activated state enzyme in complex with GTP, X-ray diffraction structure determination and analysis at 2.8 A resolution, the first structure which contains PRPP in all active sites, and 2.9 A resolution, for the second structure with PRPP in two sites and the hydrolysis products ribose-5-phosphate and diphosphate in the other sites, respectively, and a third structure of the enzyme in complex with UMP and the allosteric inhibitor CTP

Saccharolobus solfataricus

Inhibitors

Inhibitors	Comment	Organism	Structure
CTP	inhibitory allosteric regulation by CTP. The regulatory triphosphate binds at a site in the center of the tetramer changing the quaternary arrangement. The effector contacts Pro94 at the beginning of a long beta-strand in the dimer interface, which extends into a flexible loop over the active site, two flexible loops. In the inhibited state, residues, Tyr123 and Lys125 contribute to the configuration of the active site for UMP rather than PRPP binding. The C-terminal Gly216 participates in a hydrogen-bond network in the dimer interface that stabilizes the inhibited, but not the activated, state	Saccharolobus solfataricus

KM Value [mM]

KM Value [mM]	KM Value Maximum [mM]	Substrate	Comment	Organism	Structure
additional information	-	additional information	allosteric transition, structural and kinetic studies, overview	Saccharolobus solfataricus

Natural Substrates/ Products (Substrates)

Natural Substrates	Organism	Comment (Nat. Sub.)	Natural Products	Comment (Nat. Pro.)	Rev.	Reac.
uracil + 5-phospho-alpha-D-ribose 1-diphosphate	Saccharolobus solfataricus	-	UMP + diphosphate	-	?

Organism

Organism	UniProt	Comment	Textmining
Saccharolobus solfataricus	Q980Q4	-	-

Substrates and Products (Substrate)

Substrates	Comment Substrates	Organism	Products	Comment (Products)	Rev.	Reac.
uracil + 5-phospho-alpha-D-ribose 1-diphosphate	-	Saccharolobus solfataricus	UMP + diphosphate	-	?

Subunits

Subunits	Comment	Organism
tetramer	-	Saccharolobus solfataricus