Cloning and DNA sequencing of the dextranase inhibitor gene (dei) from Streptococcus sobrinus.
Some dextranase-deficient (Dex-) mutants of Streptococcus sobrinus UAB66 (serotype g) synthesize a substance which inhibits dextranase activity (S.-Y. Wanda, A. Camilli, H. M. Murchison, and R. Curtiss III, J. Bacteriol. 176:7206-7212, 1994). This substance produced by the Dex- mutant UAB108 was designated dextranase inhibitor (Dei) and identified as a protein. The Dei gene (dei) from UAB108 has been cloned into pACYC184 to yield pYA2651, which was then used to generate several subclones (pYA2653 to pYA2657). The DNA sequence of dei was determined by using Tn5seq1 transposon mutagenesis of pYA2653. The open reading frame of dei is 990 bp long. It encodes a signal peptide of 38 amino acids and a mature Dei protein of 292 amino acids with a molecular weight of 31,372. The deduced amino acid sequence of Dei shows various degrees of similarity with glucosyltransferases and glucan-binding protein and contains A and C repeating units probably involved in glucan binding. Southern hybridization results showed that the dei probe from UAB108 hybridized to the same-size fragment in S. sobrinus (serotype d and g) DNA, to a different-size fragment in S. downei (serotype h) and S. cricetus (serotype a), and not at all to DNAs from other mutans group of streptococci.
Department of Biology, Washington University, St. Louis, Missouri 63130.
J W
JW
Sun
S Y
SY
Wanda
A
A
Camilli
R
R
Curtiss
D000595:Amino Acid Sequence; D001422:Bacterial Adhesion; D001426:Bacterial Proteins / Q000235:genetics*; D001483:Base Sequence; D002352:Carrier Proteins / Q000235:genetics; D003001:Cloning, Molecular; D004269:DNA, Bacterial / Q000235:genetics; D003731:Dental Caries / Q000382:microbiology; D004926:Escherichia coli / Q000235:genetics; D015698:Genomic Library; D005964:Glucosyltransferases / Q000235:genetics; D037102:Lectins; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional; D009693:Nucleic Acid Hybridization; D015183:Restriction Mapping; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D012703:Serotyping; D013045:Species Specificity; D016986:Streptococcus sobrinus / Q000235:genetics*
D001426:Bacterial Proteins; D002352:Carrier Proteins; D004269:DNA, Bacterial; D037102:Lectins; C090543:dei protein, Streptococcus sobrinus; C037937:glucan-binding proteins; D005964:Glucosyltransferases