Mechanistic and structural studies of apoform, binary, and ternary complexes of the Arabidopsis alkenal double bond reductase At5g16970

Buhyun Youn; Sung-Jin Kim; Syed G A Moinuddin; Choonseok Lee; Diana L Bedgar; Athena R Harper; Laurence B Davin; Norman G Lewis; Chulhee Kang

doi:10.1074/jbc.M605900200

Back

Mechanistic and structural studies of apoform, binary, and ternary complexes of the Arabidopsis alkenal double bond reductase At5g16970

Journal article

Open access

Peer reviewed

Mechanistic and structural studies of apoform, binary, and ternary complexes of the Arabidopsis alkenal double bond reductase At5g16970

Buhyun Youn, Sung-Jin Kim, Syed G A Moinuddin, Choonseok Lee, Diana L Bedgar, Athena R Harper, Laurence B Davin, Norman G Lewis and Chulhee Kang

The Journal of biological chemistry, Vol.281(52), pp.40076-40088

12/29/2006

DOI: https://doi.org/10.1074/jbc.M605900200

Handle:

https://hdl.handle.net/2376/117633

PMID: 17028190

Files and links (1)

url

https://doi.org/10.1074/jbc.M605900200View

Published (Version of record) Open

Abstract

Amino Acid Sequence

Multigene Family

Aldehyde Reductase - genetics

Arabidopsis - enzymology

Guinea Pigs

Coumaric Acids - chemistry

Magnetic Resonance Spectroscopy

Molecular Sequence Data

Rats

Substrate Specificity

Crystallography, X-Ray

Apoenzymes - isolation & purification

Zinc - chemistry

Arabidopsis - genetics

Sequence Homology, Amino Acid

Aldehyde Reductase - chemistry

Aldehyde Reductase - isolation & purification

Animals

Apoenzymes - genetics

Apoenzymes - chemistry

Phenols - chemistry

Mice

Catalysis

Kinetics

In this study, we determined the crystal structures of the apoform, binary, and ternary complexes of the Arabidopsis alkenal double bond reductase encoded by At5g16970. This protein, one of 11 homologues in Arabidopsis thaliana, is most closely related to the Pinus taeda phenylpropenal double bond reductase, involved in, for example, heartwood formation. Both enzymes also have essential roles in plant defense, and can function by catalyzing the reduction of the 7-8-double bond of phenylpropanal substrates, such as p-coumaryl and coniferyl aldehydes in vitro. At5g16970 is also capable of reducing toxic substrates with the same alkenal functionality, such as 4-hydroxy-(2E)-nonenal. The overall fold of At5g16970 is similar to that of the zinc-independent medium chain dehydrogenase/reductase superfamily, the members of which have two domains and are dimeric in nature, i.e. in contrast to their original classification as being zinc-containing oxidoreductases. As provisionally anticipated from the kinetic data, the shape of the binding pocket can readily accommodate p-coumaryl aldehyde, coniferyl aldehyde, 4-hydroxy-(2E)-nonenal, and 2-alkenals. However, the enzyme kinetic data among these potential substrates differ, favoring p-coumaryl aldehyde. Tyr-260 is provisionally proposed to function as a general acid/base for hydride transfer. A catalytic mechanism for this reduction, and its applicability to related important detoxification mammalian proteins, is also proposed.

Metrics

9 Record Views

Details

Title: Mechanistic and structural studies of apoform, binary, and ternary complexes of the Arabidopsis alkenal double bond reductase At5g16970
Creators: Buhyun Youn - School of Molecular Biosciences, Washington State University, Pullman, Washington 99164-4660, USA
Sung-Jin Kim
Syed G A Moinuddin
Choonseok Lee
Diana L Bedgar
Athena R Harper
Laurence B Davin
Norman G Lewis
Chulhee Kang
Publication Details: The Journal of biological chemistry, Vol.281(52), pp.40076-40088
Academic Unit: Chemistry, Department of; Biological Chemistry, Institute of
Publisher: United States
Identifiers: 99900548094001842
Language: English
Resource Type: Journal article