Gene/Protein
Disease
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Drug
Enzyme
Compound
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Gene/Protein
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Target Concepts:
Gene/Protein
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Query: EC:3.2.1.36 (
hyaluronidase
)
4,606
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
When grown on xanthan as a carbon source, the bacterium Bacillus sp. strain GL1 produces extracellular
xanthan lyase
(75 kDa), catalyzing the first step of xanthan depolymerization (H. Nankai, W. Hashimoto, H. Miki, S. Kawai, and K. Murata, Appl. Environ. Microbiol. 65:2520-2526, 1999). A gene for the lyase was cloned, and its nucleotide sequence was determined. The gene contained an open reading frame consisting of 2,793 bp coding for a polypeptide with a molecular weight of 99,308. The polypeptide had a signal peptide (2 kDa) consisting of 25 amino acid residues preceding the N-terminal amino acid sequence of the enzyme and exhibited significant homology with
hyaluronidase
of Streptomyces griseus (identity score, 37.7%). Escherichia coli transformed with the gene without the signal peptide sequence showed a
xanthan lyase
activity and produced intracellularly a large amount of the enzyme (400 mg/liter of culture) with a molecular mass of 97 kDa. During storage at 4 degrees C, the purified enzyme (97 kDa) from E. coli was converted to a low-molecular-mass (75-kDa) enzyme with properties closely similar to those of the enzyme (75 kDa) from Bacillus sp. strain GL1, specifically in optimum pH and temperature for activity, substrate specificity, and mode of action. Logarithmically growing cells of Bacillus sp. strain GL1 on the medium with xanthan were also found to secrete not only
xanthan lyase
(75 kDa) but also a 97-kDa protein with the same N-terminal amino acid sequence as that of
xanthan lyase
(75 kDa). These results suggest that, in Bacillus sp. strain GL1,
xanthan lyase
is first synthesized as a preproform (99 kDa), secreted as a precursor (97 kDa) by a signal peptide-dependent mechanism, and then processed into a mature form (75 kDa) through excision of a C-terminal protein fragment with a molecular mass of 22 kDa.
...
PMID:Polysaccharide lyase: molecular cloning, sequencing, and overexpression of the xanthan lyase gene of Bacillus sp. strain GL1. 1115 35