1rk2
E. COLI RIBOKINASE COMPLEXED WITH RIBOSE AND ADP, SOLVED IN SPACE GROUP P212121
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OverviewOverview
The enzyme ribokinase phosphorylates ribose at O5* as the first step in, its metabolism. The original X-ray structure of Escherichia coli, ribokinase represented the ternary complex including ribose and ADP., Structures are presented here for the apo enzyme, as well as the, ribose-bound state and four new ternary complex forms. Combined, the, structures suggest that large and small conformational changes play, critical roles in the function of this kinase. An initially open apo form, can allow entry of the ribose substrate. After ribose binding, the active, site lid is observed in a closed conformation, with the sugar trapped, underneath. This closure and associated changes in the protein appear to, assist ribokinase in recognition of the co-substrate ATP as the next step., Binding of the nucleotide brings about further, less dramatic adjustments, in the enzyme structure. Additional small movements are almost certainly, required during the phosphoryltransfer reaction. Evidence is presented, that some types of movements of the lid are allowed in the ternary, complex, which may be critical to the creation and breakdown of the, transition state. Similar events are likely to take place during catalysis, by other related carbohydrate kinases, including adenosine kinase.
About this StructureAbout this Structure
1RK2 is a Single protein structure of sequence from Escherichia coli with RIB, ALF, MG and ADP as ligands. Active as Ribokinase, with EC number 2.7.1.15 Full crystallographic information is available from OCA.
ReferenceReference
Induced fit on sugar binding activates ribokinase., Sigrell JA, Cameron AD, Mowbray SL, J Mol Biol. 1999 Jul 30;290(5):1009-18. PMID:10438599
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