|
KMID : 0545120010110040693
|
|
Journal of Microbiology and Biotechnology
2001 Volume.11 No. 4 p.693 ~ p.699
|
|
|
Cloning and Sequence Analysis of a Levansucrase Gene from Rahnella aquatilis ATCC15552
|
|
Kim, Hyun Jin
Yang, Ji Young/Lee, Hyeon Gyu/Cha, Jae Ho
|
|
|
Abstract
|
|
|
|
An intracellular levansucrase gene, lscR from Rahnella aquatilis ATCC15552, was cloned and its nucleotide sequence was determined. Nucleotide sequence analysis of this gene revealed a 1,248bp open reading frame coding for a protein of 415 amino acids. The levansucrase was expressed by using a T7 promoter in Escherichia coli BL21 (DE3) and the enzyme activity was detected in the cytoplasmic fraction. The optimum pH and temperature of this enzyme for levan formation was pH 6 and 30℃, respectively. The deduced amino acid sequence of the lscR gene showed a high sequence similarity (59-89%) with Gram-negative levansucrases, while the level of similarity with Gram-positive enzymes was less than 42%. Multiple alignments of levansucrase sequences reported from Gram-negative and Gram-positive bacteria revealed seven conserved regions. A comparison of the catalytic properties and deduced amino acid sequence of lscR with those of other bacterial levansucrases strongly suggest that Gram-negative and Gram-positive levansucrases have an overall different structure, but they have a similar structure at the active site.
|
|
|
KEYWORD
|
|
|
|
|
|
FullTexts / Linksout information
|
|
|
|
|
|
Listed journal information
|
|
  
|
|