Molecular cloning, sequence analysis, and functional characterization of the lipopolysaccharide biosynthetic gene kdtA encoding 3-deoxy-alpha-D-manno-octulosonic acid transferase of Chlamydia pneumoniae strain TW-183.
The gene kdtA of Chlamydia pneumoniae strain TW-183, encoding the enzyme 3-deoxy-alpha-D-manno-octulosonic acid (Kdo) transferase of lipopolysaccharide biosynthesis, was cloned and sequenced. A single open reading frame of 1314 bp was identified, the deduced amino acid sequence of which revealed 69% similarity and 43% identity with KdtA of Chlamydia trachomatis and Chlamydia psittaci. The gene was expressed in the Gram-positive host Corynebacterium glutamicum and the primary gene product was characterized as a multifunctional glycosyltransferase. Cell-free extracts generated in vitro the genus-specific epitope of Chlamydia composed of the trisaccharide alphaKdo(2-8)alphaKdo(2-4)alphaKdo. The results show that a single polypeptide affords three different glycosidic bonds, which is in contradiction to the dogma of glycobiology: 'one enzyme - one glycosidic bond'.
Löbau
S
S
Division of Biochemical Microbiology, Forschungsinstitut Borstel, Germany.
Mamat
U
U
Brabetz
W
W
Brade
H
H
D000595:Amino Acid Sequence; D001483:Base Sequence; D015153:Blotting, Western; D016993:Chlamydophila pneumoniae / Q000235:genetics*; D003001:Cloning, Molecular; D003352:Corynebacterium / Q000235:genetics; D000939:Epitopes; D015870:Gene Expression; D005798:Genes, Bacterial; D008969:Molecular Sequence Data; D010957:Plasmids; D017421:Sequence Analysis; D017386:Sequence Homology, Amino Acid; D014166:Transferases / Q000737:chemistry / Q000235:genetics* / Q000302:isolation & purification / Q000648:ultrastructure
D000939:Epitopes; D014166:Transferases; C019917:3-deoxy-D-manno-octulosonate transferase