Involvement of glycine and aspartate residues in the binding capacity of FAD in the NADH dehydrogenase from an alkaliphilic Bacillus.
There is a region exhibiting a similarity of amino acid sequence near the carboxyl-terminal segment of each FAD-containing oxidoreductase. In this region, four amino acid residues-Thr, Ala, Gly, and Asp-are highly conserved. To determine the involvement of the four amino acid residues (Thr-469, Ala-476, Gly-478, and Asp-479) in the activity of NADH dehydrogenase of an alkaliphilic Bacillus, mutations of these amino acid residues were conducted. In spite of high conservation, mutations of Thr-469 and Ala-476 to Ala and Ser, respectively, did not lead to a critical loss of enzyme activity. However, mutations of Gly-478 and Asp-479 to Ala caused a complete loss of the activity, which appears to result from the loss of binding capacity of FAD.
Department of Chemistry, Faculty of Science, Chiba University, Yayoi, Chiba 263-8522, Japan.
Masato
M
Shiraki
Noriyuki
N
Koyama
D001224:Aspartic Acid / Q000235:genetics / Q000378:metabolism*; D001407:Bacillus / Q000201:enzymology* / Q000235:genetics; D017124:Conserved Sequence / Q000235:genetics; D005182:Flavin-Adenine Dinucleotide / Q000378:metabolism*; D005998:Glycine / Q000235:genetics / Q000378:metabolism*; D016297:Mutagenesis, Site-Directed; D009245:NADH Dehydrogenase / Q000235:genetics / Q000378:metabolism*; D013912:Threonine / Q000235:genetics / Q000378:metabolism
D005182:Flavin-Adenine Dinucleotide; D013912:Threonine; D001224:Aspartic Acid; D009245:NADH Dehydrogenase; D005998:Glycine