| Autor: |
Qin, Hui-Min, Miyakawa, Takuya, Jia, Min Ze, Nakamura, Akira, Ohtsuka, Jun, Xue, You-Lin, Kawashima, Takashi, Kasahara, Takuya, Hibi, Makoto, Ogawa, Jun, Tanokura, Masaru |
| Předmět: |
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| Zdroj: |
PLoS ONE; May2013, Vol. 8 Issue 5, p1-9, 9p |
| Abstrakt: |
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 CO2. 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/EXnH 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] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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