GlmS glucosamine-6-phosphate activated ribozyme

Glucosamine-6-phosphate activated ribozyme (GlcN6P) is found in the 5'UTR of the mRNA which is coding for GlmS . GlmS is an enzyme that uses fructose-6-phosphate and glutamine to generate glucosamine-6-phosphate. The ribozyme catalyses self cleavage of the glmS mRNA thereby regulating GlmS activity cite journal | last = Winkler | first = WC | coauthors = Nahvi A, Roth A, Collins JA, Breaker RR | year = 2004 | title = Control of gene expression by a natural metabolite-responsive ribozyme | journal = Nature | volume = 428 | pages = 281–286 | pmid = 15029187 | doi = 10.1038/nature02362] . The GlmS element is only catalytic when bound to glucosamine-6-phosphate. The glucosamine-6-phosphate is a cofactor for the catalytic reaction, directly participating in the chemistry. This is the only known case of a ribozyme using a small-molecule cofactor at present.

tructure

The structure of the GlmS ribozyme has been determined by X-ray crystallography.cite journal |author=Klein DJ, Ferré-D'Amaré AR |title=Structural basis of glmS ribozyme activation by glucosamine-6-phosphate |journal=Science |volume=313 |issue=5794 |pages=1752–6 |year=2006 |pmid=16990543 |doi=10.1126/science.1129666] cite journal |author=Cochrane JC, Lipchock SV, Strobel SA |title=Structural investigation of the GlmS ribozyme bound to Its catalytic cofactor |journal=Chem. Biol. |volume=14 |issue=1 |pages=97–105 |year=2007 |pmid=17196404 |doi=10.1016/j.chembiol.2006.12.005] The RNA adopts a double pseudoknotted structure. The cofactor is bound in a solvent-accessible pocket and the structure suggests that the amine group of GlcN6P is involved in the catalytic process.

References

*cite journal | last = Jansen | first = JA | coauthors = McCarthy TJ, Soukup GA, Soukup JK | year = 2006 | title = Backbone and nucleobase contacts to glucosamine-6-phosphate in the glmS ribozyme | journal = Nat Struct Mol Biol. | volume = 13 | pages = 517–523 | pmid = 16699515 | doi = 10.1038/nsmb1094
*cite journal | last = Hampel | first = KJ | coauthors = Tinsley MM | year = 2006 | title = Evidence for preorganization of the glmS ribozyme ligand binding pocket | journal = Biochemistry. | volume = 45 | pages = 7861–7871 | pmid = 16784238 | doi = 10.1021/bi060337z

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