CLONING AND CHARACTERIZATION OF A DEXTRANASE GENE (DEXS) FROM STREPTOCOCCUS-SUIS

A gene (dexS) coding for a Streptococcus suis capsular type 2 dextrana se (DexS) was detected in a recombinant gene library constructed in ph age lambda ZapII, and its nucleotide sequence was determined. Sequence comparison showed that the dexS gene product had significant similari ties with enzymes which hydrolyze glucose polymers. Moreover, conserve d amino acids that are suggested to be part of the active site of the glucosidases are also found in DexS. The dexS gene, adjacent to the ge ne encoding a S. suis IgG-binding protein, encoded a protein of approx imately 62 kDa which exhibited DexS activity. (C) Elsevier Science B.V .