PDBsum entry 4d5e

Hydrolase

PDB id: 4d5e

Contents

Protein chains

586 a.a.

Ligands

FAD ×2

TPP ×2

MES ×2

P6G ×2

1PG

PG4 ×9

PEG

2PE ×3

Metals

_CL ×2

_MG ×3

Waters ×970

References listed in PDB file

Key reference

• Title: Extended reaction scope of thiamine diphosphate dependent cyclohexane-1,2-Dione hydrolase: from c-C bond cleavage to c-C bond ligation.
• Authors: S.Loschonsky, T.Wacker, S.Waltzer, P.P.Giovannini, M.J.Mcleish, S.L.Andrade, M.Müller.
• Ref.: Angew Chem Int Ed Engl, 2014, 53, 14402-14406. [DOI no: 10.1002/anie.201408287]
• PubMed id: 25382418

Abstract

ThDP-dependent cyclohexane-1,2-dione hydrolase (CDH) catalyzes the CC bond cleavage of cyclohexane-1,2-dione to 6-oxohexanoate, and the asymmetric benzoin condensation between benzaldehyde and pyruvate. One of the two reactivities of CDH was selectively knocked down by mutation experiments. CDH-H28A is much less able to catalyze the CC bond formation, while the ability for CC bond cleavage is still intact. The double variant CDH-H28A/N484A shows the opposite behavior and catalyzes the addition of pyruvate to cyclohexane-1,2-dione, resulting in the formation of a tertiary alcohol. Several acyloins of tertiary alcohols are formed with 54-94 % enantiomeric excess. In addition to pyruvate, methyl pyruvate and butane-2,3-dione are alternative donor substrates for CC bond formation. Thus, the very rare aldehyde-ketone cross-benzoin reaction has been solved by design of an enzyme variant.