A bacterial enzyme degrading the model lignin compound beta-etherase is a member of the glutathione-S-transferase superfamily.
Cleavage of beta-aryl ether linkages is essential in lignin degradation. We identified another beta-etherase gene (ligF), which contains an open reading frame of 771 bp and lies between genes coding C alpha-dehydrogenase (ligD) and beta-etherase (ligE). The beta-etherase activity of LigF expressed in Escherichia coli was more than 80 times as high as that of LigE. ligF and ligE are homologous to glutathione-S-transferase, and upon addition of glutathione a remarkable acceleration of beta-etherase activity was found in E. coli carrying ligF. It is concluded that LigF plays a central role in beta-aryl ether cleavage and that glutathione is the hydrogen donor in this reaction.
Laboratory of Wood Chemistry, Faculty of Agriculture, Tokyo Noko University, Japan.
E
E
Masai
Y
Y
Katayama
S
S
Kubota
S
S
Kawai
M
M
Yamasaki
N
N
Morohoshi
D000595:Amino Acid Sequence; D001426:Bacterial Proteins; D001483:Base Sequence; D003001:Cloning, Molecular; D004269:DNA, Bacterial; D015252:Deoxyribonucleases, Type II Site-Specific / Q000378:metabolism; D004926:Escherichia coli; D005978:Glutathione / Q000378:metabolism; D005982:Glutathione Transferase / Q000378:metabolism*; D008031:Lignin / Q000378:metabolism*; D008969:Molecular Sequence Data; D010088:Oxidoreductases / Q000235:genetics* / Q000378:metabolism; D011549:Pseudomonas / Q000201:enzymology*; D015183:Restriction Mapping; D017386:Sequence Homology, Amino Acid
D001426:Bacterial Proteins; D004269:DNA, Bacterial; D008031:Lignin; D010088:Oxidoreductases; C060093:aryl ether cleaving enzyme; D005982:Glutathione Transferase; D015252:Deoxyribonucleases, Type II Site-Specific; C029792:GTCGAC-specific type II deoxyribonucleases; D005978:Glutathione