4meg

In vitro evolved glmS ribozyme triple mutant, magnesium ion complex

spinqualitylabelsall models 4meg, resolution 3.10Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 4meg is a 2 chain structure with sequence from Caldanaerobacter subterraneus subsp. tengcongensis. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 3.1Å Ligands: MG Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Publication Abstract from PubMed Uniquely among known ribozymes, the glmS ribozyme-riboswitch requires a small-molecule coenzyme, glucosamine-6-phosphate (GlcN6P). Although consistent with its gene-regulatory function, the use of GlcN6P is unexpected because all of the other characterized self-cleaving ribozymes use RNA functional groups or divalent cations for catalysis. To determine what active site features make this ribozyme reliant on GlcN6P and to evaluate whether it might have evolved from a coenzyme-independent ancestor, we isolated a GlcN6P-independent variant through in vitro selection. Three active site mutations suffice to generate a highly reactive RNA that adopts the wild-type fold but uses divalent cations for catalysis and is insensitive to GlcN6P. Biochemical and crystallographic comparisons of wild-type and mutant ribozymes show that a handful of functional groups fine-tune the RNA to be either coenzyme or cation dependent. These results indicate that a few mutations can confer new biochemical activities on structured RNAs. Thus, families of structurally related ribozymes with divergent function may exist. An in vitro evolved glmS ribozyme has the wild-type fold but loses coenzyme dependence.,Lau MW, Ferre-D'Amare AR Nat Chem Biol. 2013 Oct 6. doi: 10.1038/nchembio.1360. PMID:24096303 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Ribozyme 3D structures

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