Demonstration of UDP-glucose dehydrogenase activity in cell extracts of Escherichia coli expressing the pneumococcal cap3A gene required for the synthesis of type 3 capsular polysaccharide.
The gene cluster of Streptococcus pneumoniae coding for the type 3 capsular polysaccharide contains four genes (cap3ABCD). A DNA fragment containing the cap3A gene was amplified by PCR and cloned under the control of a T7 RNA polymerase-dependent promoter. Overexpression of this gene in Escherichia coli resulted both in a 47-kDa protein in the cytoplasm of isopropyl-beta-D-thiogalactopyranoside-induced bacteria and in high levels of UDP-glucose dehydrogenase activity. These data demonstrate, in a direct experimental way, that cap3A encodes the UDP-glucose dehydrogenase of pneumococcus type 3.
Arrecubieta
C
C
Departamento de Microbiología Molecular, Centro de Investigaciones Biológicas, Madrid, Spain.
García
E
E
López
R
R
D016667:Bacterial Capsules / Q000096:biosynthesis*; D001426:Bacterial Proteins / Q000235:genetics* / Q000302:isolation & purification; D001483:Base Sequence; D004926:Escherichia coli / Q000235:genetics; D005798:Genes, Bacterial; D008969:Molecular Sequence Data; D011994:Recombinant Proteins / Q000302:isolation & purification; D013296:Streptococcus pneumoniae / Q000201:enzymology / Q000235:genetics*; D014533:Uridine Diphosphate Glucose Dehydrogenase / Q000235:genetics* / Q000302:isolation & purification
D001426:Bacterial Proteins; D011994:Recombinant Proteins; C081697:Cap3a protein, Streptococcus pneumoniae; D014533:Uridine Diphosphate Glucose Dehydrogenase