3ry7
Crystal Structure of Sa239
Structural highlights
FunctionRBSK_STAAC Catalyzes the phosphorylation of ribose at O-5 in a reaction requiring ATP and magnesium. The resulting D-ribose-5-phosphate can then be used either for sythesis of nucleotides, histidine, and tryptophan, or as a component of the pentose phosphate pathway.[HAMAP-Rule:MF_01987][1] Publication Abstract from PubMedRibokinase is responsible for catalyzing the reaction of d-ribose and ATP to produce ribose-5-phosphate and ADP, which can be activated by monovalent cations such as potassium, cesium and ammonium. However, the exact activation mechanism of ribokinase remains elusive. Here we report the crystal structure of Sa239, a ribokinase from Staphylococcus aureus, in the absence of monovalent ions. In addition to the dimer form similar to that observed in Escherichia coli ribokinase structure, the structure of Sa239 demonstrates that the C-terminal tail protrudes from the remaining part and interacts with the neighboring molecule, resulting in an unexpected dimerization form. By comparing the structure of Sa239 to E. coli ribokinase, we propose that binding of the monovalent cation triggers the conformational change of the large ATP loop to organize the formation of nucleotide binding pocket, thus enabling ATP binding and enhancing catalytic activity. Our study uncovers the detailed structural basis for the activation mechanism of ribokinase by monovalent cations. Crystal structure of Sa239 reveals the structural basis for the activation of ribokinase by monovalent cations.,Li J, Wang C, Wu Y, Wu M, Wang L, Wang Y, Zang J J Struct Biol. 2012 Feb;177(2):578-82. Epub 2011 Dec 16. PMID:22198595[2] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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