5l50

Crystal structure of enzyme in purine metabolism

spinqualitylabelsall models 5l50, resolution 1.64Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 5l50 is a 1 chain structure with sequence from Homo sapiens. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 1.643Å Ligands: GOL Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Disease 5NTC_HUMAN Autosomal recessive spastic paraplegia type 45. The disease is caused by mutations affecting the gene represented in this entry. Function 5NTC_HUMAN May have a critical role in the maintenance of a constant composition of intracellular purine/pyrimidine nucleotides in cooperation with other nucleotidases. Preferentially hydrolyzes inosine 5'-monophosphate (IMP) and other purine nucleotides. Publication Abstract from PubMed BACKGROUND: Relapsed acute lymphoblastic leukemia (ALL) is one of the main causes of mortality in childhood malignancies. Previous genetic studies demonstrated that chemoresistant ALL is driven by activating mutations in NT5C2, the gene encoding cytosolic 5 -nucleotidase (cN-II). However, molecular mechanisms underlying this hyperactivation are still unknown. Here, we present kinetic and structural properties of cN-II variants that represent 75 % of mutated alleles in patients who experience relapsed ALL (R367Q, R238W and L375F). RESULTS: Enzyme kinetics measurements revealed that the mutants are consitutively active without need for allosteric activators. This shows that hyperactivity is not caused by a direct catalytic effect but rather by misregulation of cN-II. X-ray crystallography combined with mass spectrometry-based techniques demonstrated that this misregulation is driven by structural modulation of the oligomeric interface within the cN-II homotetrameric assembly. These specific conformational changes are shared between the studied variants, despite the relatively random spatial distribution of the mutations. CONCLUSIONS: These findings define a common molecular mechanism for cN-II hyperactivity, which provides a solid basis for targeted therapy of leukemia. Our study highlights the cN-II oligomerization interface as an attractive pharmacological target. Oligomeric interface modulation causes misregulation of purine 5 -nucleotidase in relapsed leukemia.,Hnizda A, Skerlova J, Fabry M, Pachl P, Sinalova M, Vrzal L, Man P, Novak P, Rezacova P, Veverka V BMC Biol. 2016 Oct 19;14(1):91. PMID:27756303 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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