Implications of phase variation of a gene (pgtA) encoding a pilin galactosyl transferase in gonococcal pathogenesis.
The pilin glycoprotein (PilE) is the main building block of the pilus of Neisseria gonorrhoeae (gonococcus [GC]). GC pilin is known to carry a disaccharide O-glycan, which has an alphaGal attached to the O-linked GlcNAc by a 1-3 glycosidic bond. In this report, we describe the cloning and characterization of the GC gene, pilus glycosyl transferase A (pgtA), which encodes the galactosyl transferase that catalyzes the synthesis of this Gal-GlcNAc bond of pilin glycan. A homopolymeric tract of Gs (poly-G) is present in the pgtA gene of many GC strains, and this pgtA with poly-G can undergo phase variation (Pv). However, in many other GC, pgtA lacks the poly-G and is expressed constitutively without Pv. Furthermore, by screening a large number of clinical isolates, a significant correlation was observed between the presence of poly-G in pgtA and the dissemination of GC infection. Poly-G was found in pgtA in all (24 out of 24) of the isolates from patients with disseminated gonococcal infection (DGI). In contrast, for the vast majority (20 out of 28) of GC isolated from uncomplicated gonorrhea (UG) patients, pgtA lacked the poly-G. These results indicate that Pv of pgtA is likely to be involved in the conversion of UG to DGI.
Department of Biology, The Catholic University of America, Washington, DC 20064, USA. banerjee@cua.edu
Asesh
A
Banerjee
Rong
R
Wang
Sherry L
SL
Supernavage
Salil K
SK
Ghosh
James
J
Parker
Nisha F
NF
Ganesh
Peng G
PG
Wang
Sunita
S
Gulati
Peter A
PA
Rice
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000096:biosynthesis* / Q000737:chemistry; D001483:Base Sequence; D003001:Cloning, Molecular; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D005260:Female; D036781:Fimbriae Proteins; D005700:Galactosyltransferases / Q000235:genetics* / Q000378:metabolism*; D015870:Gene Expression; D005798:Genes, Bacterial; D006069:Gonorrhea / Q000382:microbiology; D006801:Humans; D008297:Male; D013058:Mass Spectrometry; D008562:Membrane Glycoproteins / Q000096:biosynthesis* / Q000737:chemistry; D008969:Molecular Sequence Data; D009344:Neisseria gonorrhoeae / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism* / Q000472:pathogenicity; D011068:Poly G / Q000737:chemistry; D017386:Sequence Homology, Amino Acid; D012689:Sequence Homology, Nucleic Acid; D014774:Virulence / Q000235:genetics
D001426:Bacterial Proteins; D004269:DNA, Bacterial; D008562:Membrane Glycoproteins; C074063:pilE protein, Neisseria gonorrhoeae; D036781:Fimbriae Proteins; D011068:Poly G; D005700:Galactosyltransferases