Purification and characterization of an active N-acetylglucosaminyltransferase enzyme complex from Streptococci.
A new family of bacterial serine-rich repeat glycoproteins can function as adhesins required for biofilm formation and pathogenesis in streptococci and staphylococci. Biogenesis of these proteins depends on a gene cluster coding for glycosyltransferases and accessory secretion proteins. Previous studies show that Fap1, a member of this family from Streptococcus parasanguinis, can be glycosylated by a protein glycosylation complex in a recombinant heterogeneous host. Here we report a tandem affinity purification (TAP) approach used to isolate and study protein complexes from native streptococci. This method demonstrated that a putative glycosyltransferase (Gtf2), which is essential for Fap1 glycosylation, readily copurified with another glycosyltransferase (Gtf1) from native S. parasanguinis. This result and the similar isolation of a homologous two-protein complex from Streptococcus pneumoniae indicate the biological relevance of the complexes to the glycosylation in streptococci. Furthermore, novel N-acetylglucosaminyltransferase activity was discovered for the complexes. Optimal activity required heterodimer formation and appears to represent a novel type of glycosylation.
Department of Pediatric Dentistry, School of Dentistry, University of Alabama at Birmingham, Birmingham, Alabama 35294, USA.
Ren
R
Wu
Meixian
M
Zhou
Hui
H
Wu
D000595:Amino Acid Sequence; D002846:Chromatography, Affinity / Q000379:methods; D019281:Dimerization; D036781:Fimbriae Proteins / Q000378:metabolism; D006031:Glycosylation; D008969:Molecular Sequence Data; D017351:N-Acetylglucosaminyltransferases / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism*; D013291:Streptococcus / Q000201:enzymology*
C403708:fap1 protein, Streptococcus; D036781:Fimbriae Proteins; D017351:N-Acetylglucosaminyltransferases; C037649:N-acetyllactosaminide beta-1,6-N-acetylglucosaminyltransferase