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Crystal Structure of a Novel N-Substituted L-Amino Acid Dioxygenase from Burkholderia ambifaria AMMD
- Source :
- PLoS ONE; May2013, Vol. 8 Issue 5, p1-9, 9p
- Publication Year :
- 2013
-
Abstract
- A novel dioxygenase from Burkholderia ambifaria AMMD (SadA) stereoselectively catalyzes the C3-hydroxylation of N-substituted branched-chain or aromatic L-amino acids, especially N-succinyl-L-leucine, coupled with the conversion of α-ketoglutarate to succinate and CO<subscript>2</subscript>. To elucidate the structural basis of the substrate specificity and stereoselective hydroxylation, we determined the crystal structures of the SadA.Zn(II) and SadA.Zn(II).α-KG complexes at 1.77 Å and 1.98 Å resolutions, respectively. SadA adopted a double-stranded β-helix fold at the core of the structure. In addition, an HXD/EX<subscript>n</subscript>H motif in the active site coordinated a Zn(II) as a substitute for Fe(II). The α-KG molecule also coordinated Zn(II) in a bidentate manner via its 1-carboxylate and 2-oxo groups. Based on the SadA.Zn(II).α-KG structure and mutation analyses, we constructed substrate-binding models with N-succinyl-L-leucine and N-succinyl-L-phenylalanine, which provided new insight into the substrate specificity. The results will be useful for the rational design of SadA variants aimed at the recognition of various N-succinyl L-amino acids. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 19326203
- Volume :
- 8
- Issue :
- 5
- Database :
- Complementary Index
- Journal :
- PLoS ONE
- Publication Type :
- Academic Journal
- Accession number :
- 88376378
- Full Text :
- https://doi.org/10.1371/journal.pone.0063996