원문정보
초록
영어
L-Fucose dehydrogenase (FDH) from Burkholderia cepacia (KCTC 2966) is a NAD-dependent member of short-chain dehydrogenase/reductase (SDR) superfamily and has 258 amino acid residues. Although the SDR is a large family of enzymes, little is known about the residues affecting the enzyme specificity, especially for aldose SDRs. We conjectured glutamic acid-183 as an essential residue for enzyme activity by multiple sequences alignment within aldose SDR members and comparison of substrate binding site structures. In order to confirm the role of this residue, we constructed several mutants of FDH, in which glutamic acid-183 was substituted with other amino acids having different chemical properties, by site-directed mutagenesis. The activity test results with these mutants showed drastic loss of enzyme activity. Other residues that possibly participate in substrate binding were also examined. This work shows that the important residues for enzyme specificity can be identified, without determining the crystal structure of enzyme, by investigating the pre-existing sequence database and 3D structure models of the same protein family.