4ts5 | pdb_00004ts5

Sulfolobus solfataricus adenine phosphoribosyltransferase with AMP

spinqualitylabelsall models 4ts5, resolution 2.40Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 4ts5 is a 2 chain structure with sequence from Saccharolobus solfataricus. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: AMP, PO4 Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function Q97W95_SACS2 Publication Abstract from PubMed The adenine phosphoribosyltransferase (APRTase) encoded by the open reading frame SSO2342 of Sulfolobus solfataricus P2 was subjected to crystallographic, kinetic, and ligand binding analyses. The enzyme forms dimers in solution and in the crystals, and binds one molecule of the reactants 5-phosphoribosyl-alpha-1-pyrophosphate (PRPP) and adenine or the product adenosine monophosphate (AMP) or the inhibitor adenosine diphosphate (ADP) in each active site. The individual subunit adopts an overall structure that resembles a 6-oxopurine phosphoribosyltransferase (PRTase) more than known APRTases implying that APRT functionality in Crenarchaeotae has its evolutionary origin in this family of PRTases. Only the N-terminal two-thirds of the polypeptide chain folds as a traditional type I PRTase with a five-stranded beta-sheet surrounded by helices. The C-terminal third adopts an unusual three-helix bundle structure that together with the nucleobase-binding loop undergoes a conformational change upon binding of adenine and phosphate resulting in a slight contraction of the active site. The inhibitor ADP binds like the product AMP with both the alpha- and beta-phosphates occupying the 5'-phosphoribosyl binding site. The enzyme shows activity over a wide pH range, and the kinetic and ligand binding properties depend on both pH and the presence/absence of phosphate in the buffers. A slow hydrolysis of PRPP to ribose 5-phosphate and pyrophosphate, catalyzed by the enzyme, may be facilitated by elements in the C-terminal three-helix bundle part of the protein. Adenine Phosphoribosyltransferase from Sulfolobus solfataricus Is an Enzyme with Unusual Kinetic Properties and a Crystal Structure that Suggests It Evolved from a 6-Oxopurine Phosphoribosyltransferase.,Jensen KF, Hansen MR, Jensen KS, Christoffersen S, Poulsen JC, Molgaard A, Kadziola A Biochemistry. 2015 Mar 30. PMID:25790177 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Phosphoribosyltransferase 3D structures

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