Structural and Functional Influence of the Glycine-Rich Loop G302GGGY on the Catalytic Tyrosine of Histone Deacetylase 8
| Autor: | Nicolas H. Christianson, Christophe Decroos, Nicholas J. Porter, David W. Christianson |
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| Rok vydání: | 2016 |
| Předmět: | |
| Zdroj: | Biochemistry. 55:6718-6729 |
| ISSN: | 1520-4995 0006-2960 |
| Popis: | Histone deacetylase 8 (HDAC8) catalyzes the hydrolysis of acetyl-l-lysine to yield products l-lysine and acetate through a mechanism in which a nucleophilic water molecule is activated by a histidine general base and a catalytic metal ion (Zn2+ or Fe2+). Acetyl-l-lysine also requires activation by metal coordination and a hydrogen bond with catalytic tyrosine Y306, which also functions in transition state stabilization. Interestingly, Y306 is located in the conserved glycine-rich loop G302GGGY. The potential flexibility afforded by the tetraglycine segment may facilitate induced-fit conformational changes in Y306 between “in” and “out” positions, as observed in related deacetylases. To probe the catalytic importance of the glycine-rich loop in HDAC8, we rigidified this loop by preparing the G302A, G303A, G304A, and G305A mutants and measured their steady state kinetics and determined their X-ray crystal structures. Substantial losses of catalytic efficiency are observed (10–500-fold based on kcat/KM), par... |
| Databáze: | OpenAIRE |
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