Characterization of the Streptococcus mutans GS-5 fruA gene encoding exo-beta-D-fructosidase
| Autor: | Jana E.C. Penders, Robert A. Burne |
|---|---|
| Rok vydání: | 1992 |
| Předmět: |
DNA
Bacterial Signal peptide Glycoside Hydrolases Levanase Molecular Sequence Data Restriction Mapping Immunology Sequence alignment Biology Microbiology Streptococcus mutans Bacterial Proteins Consensus sequence Amino Acid Sequence Promoter Regions Genetic Peptide sequence chemistry.chemical_classification Base Sequence Nucleic acid sequence Gene Expression Regulation Bacterial biology.organism_classification Molecular biology Amino acid Infectious Diseases Streptococcus salivarius chemistry Biochemistry Genes Bacterial Nucleic Acid Conformation Parasitology Sequence Alignment Research Article |
| Zdroj: | Infection and Immunity. 60:4621-4632 |
| ISSN: | 1098-5522 0019-9567 |
| DOI: | 10.1128/iai.60.11.4621-4632.1992 |
| Popis: | The complete nucleotide sequence (5,010 bp) of the fructanase gene (fruA) and flanking regions of the chromosome of Streptococcus mutans GS-5 was determined. The fruA gene appears to be the sole transcript arising from a proximal promoter. The presumed precursor of the secreted FruA protein consists of 1,423 amino acids, and it has an M(r) of 158,656 and a pI of 4.82. The N terminus of FruA has characteristics in common with signal peptides of gram-positive organisms. The C terminus consists of a serine- and threonine-rich region, followed by the peptide LPDTGD, 4 charged amino acids, 21 amino acids with a strongly hydrophobic character, and a charged pentapeptide tail, which are proposed to correspond to the wall-spanning region, the LPXTGX consensus sequence, and the membrane-spanning domains of surface-associated proteins of gram-positive cocci. The FruA protein has significant homology with the Bacillus subtilis levanase (SacC), the Bacteroides fragilis levanase (ScrL), yeast invertases, and a number of other beta-fructosidases but not with fructosyltransferase, glucosyltransferases, or glucan-binding proteins of oral streptococci. Genes with homology to fruA were detected in S. mutans serotype c, e, and f strains, Streptococcus rattus, Streptococcus salivarius, and Streptococcus sanguis. A deletion derivative of FruA lacking the C-terminal 437 amino acids was still functional and could hydrolyze beta-(2,6)- and beta-(2,1)-linked sugars, but with altered preference for substrates. The data begin to define functional domains of the FruA protein and potential regulatory sites for induction, repression, growth rate control, and posttranslational localization of this multifunctional enzyme. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|