Cloning and Characterization of the Gene Encoding a Novelβ-Galactosidase fromBacillus circulans

The Discoidin Domain ofBacillus circulansβ-Galactosidase Plays an Essential Role in Repressing Galactooligosaccharide Production

“…12,13) Among the point-mutated forms, rBgaD-A W1540A and rBgaD-A W1540F showed lower U o-NPG /U lactose ratios.…”

“…[1][2][3][4] Hence a number of attempts to isolate -galactosidases with high transgalactosylation activities from various microorganisms have been reported, [5][6][7][8][9][10][11][12][13] and genes that encode -galactosidases, [13][14][15][16][17][18][19][20][21][22][23][24] including those of B. circulans ATCC 31382, 13,24) have been cloned. However, the lack of a crystal structure as well as a lack of knowledge of the multimeric and monomeric structures of a number of high molecular weight -galactosidases, except for Escherichia coli -galactosidase, 25) has been a drawback to developing an understanding of the mechanism of transgalactosylation.…”

Causes of the Production of Multiple Forms of β-Galactosidase byBacillus circulans

“…[8][9][10][11] Because of this, a number of studies have reported attempts to isolate a -galactosidase with high transgalactosylation activity from various microorganisms, [4][5][6][7][8] including Bacillus circulans, 12,13) Bifidobacterium adolescentis, 14) Lactobacillus reuteri, 15,16) and others. [17][18][19][20] Furthermore, the genes that encode -galactosidases from bacteria, including B. circulans, 21) Bifidobacterium bifidum [22][23][24][25] / Bifidobacterium infantis, 22,[26][27][28] L. reuteri, 29) L. plantarum, 30) and others, 20,31) have been cloned and sequenced, and the enzymes have been overexpressed in heterologous cells.…”

“…Ajisaka et al [46][47][48] expressed a -galactosidase gene in E. coli cells cloned from y To whom correspondence should be addressed. Tel/Fax: +81-86-251-8200; E-mail: kazuhiro@cc.okayama-u.ac.jp Abbreviations: BSA, bovine serum albumin; EDTA, ethylenediaminetetraacetic acid; GOS, galactooligosaccharides; HPLC, high performance liquid chromatography; MALDI/TOF MS, matrix-assisted laser desorption/ionization, time-of-flight mass spectrometry; MU, 4-methylumbelliferone; MUGA, 4-methylumbelliferyl -galactoside; o-NP, o-nitrophenol; o-NPF, o-nitrophenyl -D-fucopyranoside; p-NPF, p-nitrophenyl -D-fucopyranoside; o-NPG, o-nitrophenyl -D-galactopyranoside; p-NPG, p-nitrophenyl -D-galactopyranoside; PCMB, p-chloromercuribenzoic acid; TFA, trifluoroacetic acid B. circulans ATCC 31382, and used it to synthesize functional galactosylated compounds, but its calculated molecular mass was only 66.9 kDa, 21) much smaller than the -galactosidase-1 and -galactosidase-2 isolated from Biolacta Ò . Thus ambiguities concerning thegalactosidases produced by B. circulans ATCC 31382 clearly exist.…”

Cloning, nucleotide sequencing, and expression of the .BETA.-galactosidase-encoding gene (lacA) from Aspergillus oryzae.

“…AL356992), Bacillus circulans (Ito and Sasaki, 1997), Arthrobacter (Gutshall et al, 1995), and Xanthomonas manihotis (Taron et al, 1995) (Table 1). These b-gals are classified in family 35 glycosyl hydrolases (Henrissat and Bairoch, 1993).…”