Threonine 57 is required for the post-translational activation of Escherichia coli aspartate α-decarboxylase.
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.
Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds LS2 9JT, England.
Michael E
ME
Webb
Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds LS2 9JT, England.
Briony A
BA
Yorke
Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge CB2 1QW, England.
Tom
T
Kershaw
School of Chemistry, University of Leeds, Leeds LS2 9JT, England.
Sarah
S
Lovelock
Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge CB2 1QW, England.
Carina M C
CM
Lobley
Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge CB2 1QW, England.
Mairi L
ML
Kilkenny
Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EA, England.
Alison G
AG
Smith
Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge CB2 1QW, England.
Tom L
TL
Blundell
Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds LS2 9JT, England.
Arwen R
AR
Pearson
University Chemical Laboratory, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, England.
Chris
C
Abell
D004789:Enzyme Activation; D004926:Escherichia coli / Q000201:enzymology*; D005968:Glutamate Decarboxylase / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D008958:Models, Molecular; D009154:Mutation; D017434:Protein Structure, Tertiary; D013912:Threonine / Q000235:genetics / Q000378:metabolism
D013912:Threonine; C019104:aspartate-alpha-decarboxylase; D005968:Glutamate Decarboxylase
amino-acid-derived cofactors; aspartate decarboxylase; post-translational modification; pyruvoyl-dependent