GlmS glucosamine-6-phosphate activated ribozyme

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glmS glucosamine-6-phosphate activated ribozyme

Type:	Cis-reg; riboswitch;
2° structure:	Published; PubMed
Seed alignment:	Barrick JE, Breaker RR
Avg length:	186.5 nucleotides
Avg identity:	60%

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 ^[1]. 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.

[edit] Structure

The structure of the GlmS ribozyme has been determined by X-ray crystallography.^[2]^[3] 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.

[edit] References

^ Winkler, WC; Nahvi A, Roth A, Collins JA, Breaker RR (2004). "Control of gene expression by a natural metabolite-responsive ribozyme". Nature 428: 281–286. doi:10.1038/nature02362. PMID 15029187.
^ Klein DJ, Ferré-D'Amaré AR (2006). "Structural basis of glmS ribozyme activation by glucosamine-6-phosphate". Science 313 (5794): 1752–6. doi:10.1126/science.1129666. PMID 16990543.
^ Cochrane JC, Lipchock SV, Strobel SA (2007). "Structural investigation of the GlmS ribozyme bound to Its catalytic cofactor". Chem. Biol. 14 (1): 97–105. doi:10.1016/j.chembiol.2006.12.005. PMID 17196404.

Jansen, JA; McCarthy TJ, Soukup GA, Soukup JK (2006). "Backbone and nucleobase contacts to glucosamine-6-phosphate in the glmS ribozyme". Nat Struct Mol Biol. 13: 517–523. doi:10.1038/nsmb1094. PMID 16699515.
Hampel, KJ; Tinsley MM (2006). "Evidence for preorganization of the glmS ribozyme ligand binding pocket". Biochemistry. 45: 7861–7871. doi:10.1021/bi060337z. PMID 16784238.