Threonine 57 is Required for the Post-Translational Activation of Escherichia Coli Aspartate Alpha-Decarboxylase
Webb, M.E., Yorke, B.A., Kershaw, T., Lovelock, S., Lobley, C.M.C., Kilkenny, M.L., Smith, A.G., Blundell, T.L., Pearson, A.R., Abell, C.(2014) Acta Crystallogr D Biol Crystallogr 70: 1166
- PubMed: 24699660 
- DOI: https://doi.org/10.1107/S1399004713034275
- Primary Citation of Related Structures:  
4AZD - PubMed Abstract: 
Aspartate α-decarboxylase is a pyruvoyl-dependent decarboxylase required for the production of β-alanine in the bacterial pantothenate (vitamin B5) biosynthesis pathway. The pyruvoyl group is formed via the intramolecular rearrangement of a serine residue to generate a backbone ester intermediate which is cleaved to generate an N-terminal pyruvoyl group. Site-directed mutagenesis of residues adjacent to the active site, including Tyr22, Thr57 and Tyr58, reveals that only mutation of Thr57 leads to changes in the degree of post-translational activation. The crystal structure of the site-directed mutant T57V is consistent with a non-rearranged backbone, supporting the hypothesis that Thr57 is required for the formation of the ester intermediate in activation.
Organizational Affiliation: 
Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds LS2 9JT, England.