Nucleotide sequencing and transcriptional analysis of two tandem genes encoding glucosyltransferase (water-soluble-glucan synthetase) in Streptococcus cricetus HS-6.
Two tandem genes encoding glucosyltransferase synthesizing water-soluble glucan (GTF-S) were cloned from the lambda gene library of Streptococcus cricetus HS-6 (serotype a) using anti-GTF-S antibody, and the nucleotide sequences were analyzed. The two genes (ORF1 and ORF2) were identified as streptococcal glucosyltransferases based on the following evidence: [1] the deduced amino acid sequences of their products have an active site for catalytic action and C-terminal repeated units for dextran binding, and [2] a homology search revealed that the ORF1 and ORF2 products are homologous to the GtfS protein (77.4%) of S. downei Mfe28 and GtfT protein (83.8%) of S. sobrinus OMZ176, respectively, which are both known to have GTF-S activity. Therefore, ORF1 and ORF2 might be designated gtfS and gtfT of S. cricetus, respectively. A Northern blotting and RNase protection assay suggested that the gtfS and gtfT of S. cricetus are transcribed as a single bicistronic mRNA as well as separate monocistronic mRNAs. Primer extension analysis indicated multiple transcriptional start points for each gene.
Inoue
M
M
Department of Microbiology, Okayama University Dental School, Okayama, Japan.
Inoue
T
T
Miyagi
A
A
Tanimoto
I
I
Shingaki
R
R
Ohta
H
H
Fukui
K
K
D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D005964:Glucosyltransferases / Q000737:chemistry / Q000235:genetics*; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D013291:Streptococcus / Q000201:enzymology*; D014158:Transcription, Genetic
D005964:Glucosyltransferases