Premium
Mutations affecting the internal equilibrium of the reaction catalyzed by 6‐aminohexanoate‐dimer hydrolase
Author(s) -
Negoro Seiji,
Kawashima Yasuyuki,
Shibata Naoki,
Kobayashi Tatsuya,
Baba Takeshi,
Lee YoungHo,
Kamiya Katsumasa,
Shigeta Yasuteru,
Nagai Keisuke,
Takehara Ikki,
Kato Daiichiro,
Takeo Masahiro,
Higuchi Yoshiki
Publication year - 2016
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1002/1873-3468.12354
Subject(s) - protein data bank (rcsb pdb) , dimer , hydrolase , active site , stereochemistry , chemistry , enzyme , crystallography , biochemistry , organic chemistry
The enzyme 6‐aminohexanoate‐dimer hydrolase catalyzes amide synthesis. The yield of this reverse reaction in 90% t ‐butyl alcohol was found to vary drastically when enzyme mutants with substitutions of several amino acids located at the entrance of the catalytic cleft were used. Movement of the loop region and the flip‐flop of Tyr170 generate a local hydrophobic environment at the catalytic center of the enzyme. Here, we propose that the shift of the internal equilibrium between the enzyme–substrate complex and enzyme–product complex by the ‘water‐excluding effect’ alters the rate of the forward and reverse reactions. Moreover, we suggest that the local hydrophobic environment potentially provides a reaction center suitable for efficient amide synthesis. Database PDB code 3VWL : Hyb‐24DNY‐S 187 PDB code 3VWM : Hyb‐24DNY‐A 187 PDB code 3VWN : Hyb‐24DNY‐G 187 PDB code 3A65 : Hyb‐24DN‐A 112 /Ahx complex PDB code 3A66 : Hyb‐24DNY‐A 112 /Ahx complex PDB code 3VWP : Hyb‐24DNY‐S 187 A 112 /Ahx complex PDB code 3VWQ : Hyb‐24DNY‐A 187 A 112 /Ahx complex PDB code 3VWR : Hyb‐24DNY‐G 187 A 112 /Ahx complex