title: Streptococcus mutans serotype c tagatose 6-phosphate pathway gene cluster.
abstract: DNA cloned into Escherichia coli K-12 from a serotype c strain of Streptococcus mutans encodes three enzyme activities for galactose utilization via the tagatose 6-phosphate pathway: galactose 6-phosphate isomerase, tagatose 6-phosphate kinase, and tagatose-1,6-bisphosphate aldolase. The genes coding for the tagatose 6-phosphate pathway were located on a 3.28-kb HindIII DNA fragment. Analysis of the tagatose proteins expressed by recombinant plasmids in minicells was used to determine the sizes of the various gene products. Mutagenesis of these plasmids with transposon Tn5 was used to determine the order of the tagatose genes. Tagatose 6-phosphate isomerase appears to be composed of 14- and 19-kDa subunits. The sizes of the kinase and aldolase were found to be 34 and 36 kDa, respectively. These values correspond to those reported previously for the tagatose pathway enzymes in Staphylococcus aureus and Lactococcus lactis.
authors.affiliation: Department of Microbiology, University of Alabama, Birmingham 35294.
authors.forename: E K
authors.initials: EK
authors.lastname: Jagusztyn-Krynicka
authors.forename: J B
authors.initials: JB
authors.lastname: Hansen
authors.forename: V L
authors.initials: VL
authors.lastname: Crow
authors.forename: T D
authors.initials: TD
authors.lastname: Thomas
authors.forename: A L
authors.initials: AL
authors.lastname: Honeyman
authors.forename: R
authors.initials: R
authors.lastname: Curtiss
mesh_terms: D000446:Aldehyde-Lyases / Q000235:genetics*; D019747:Aldose-Ketose Isomerases; D002238:Carbohydrate Epimerases / Q000235:genetics*; D003001:Cloning, Molecular; D004926:Escherichia coli / Q000235:genetics; D005690:Galactose / Q000378:metabolism; D006600:Hexosephosphates / Q000378:metabolism; D005810:Multigene Family / Q000235:genetics*; D016254:Mutagenesis, Insertional; D010770:Phosphotransferases / Q000235:genetics*; D017853:Phosphotransferases (Alcohol Group Acceptor); D011994:Recombinant Proteins / Q000096:biosynthesis; D012703:Serotyping; D013295:Streptococcus mutans / Q000235:genetics*
chemical_list: D006600:Hexosephosphates; D011994:Recombinant Proteins; C026634:tagatose 6-phosphate; D010770:Phosphotransferases; D017853:Phosphotransferases (Alcohol Group Acceptor); C032258:tagatose kinase; C432824:tagatose 6-phosphate kinase; D000446:Aldehyde-Lyases; C023093:tagatose 1,6-diphosphate aldolase; D002238:Carbohydrate Epimerases; D019747:Aldose-Ketose Isomerases; C023084:galactose-6-phosphate isomerase; D005690:Galactose