Molecular genetics of glucan metabolism in oral streptococci

Computer analysis of the primary amino acid sequences deduced from nucleotide sequences of cloned genes from Streptococcus mutans and Strep. downei was used to examine features of enzymes involved in formation and degradation of glucans. All 4 glucosyltransferases for which sequence data are available show a common structure characterized by a series of reiterated repeats in the carboxy-terminal one third of the molecule. These repeats are also found in Strep. mutans glucan-binding protein and resemble those found in enzymes from other bacteria with binding properties.