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Nucleotide Sequencing and Transcriptional Analysis of Two Tandem Genes Encoding Glucosyltransferase (Water‐Soluble‐Glucan Synthetase) in Streptococcus cricetus HS‐6
Author(s) -
Inoue Miho,
Inoue Tetsuyoshi,
Miyagi Atsushi,
Tanimoto Ichiro,
Shingaki Ryuji,
Ohta Hiroyuki,
Fukui Kazuhiro
Publication year - 2000
Publication title -
microbiology and immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.664
H-Index - 70
eISSN - 1348-0421
pISSN - 0385-5600
DOI - 10.1111/j.1348-0421.2000.tb02560.x
Subject(s) - glucosyltransferase , biology , primer extension , gene , nucleic acid sequence , microbiology and biotechnology , homology (biology) , peptide sequence , biochemistry , nucleotide , genetics
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.