Glycosylation and biogenesis of a family of serine-rich bacterial adhesins.
Glycosylation of bacterial proteins is an important process for bacterial physiology and pathophysiology. Both O- and N-linked glycan moieties have been identified in bacterial glycoproteins. The N-linked glycosylation pathways are well established in Gram-negative bacteria. However, the O-linked glycosylation pathways are not well defined due to the complex nature of known O-linked glycoproteins in bacteria. In this review, we examine a new family of serine-rich O-linked glycoproteins which are represented by fimbriae-associated adhesin Fap1 of Streptococcus parasanguinis and human platelet-binding protein GspB of Streptococcus gordonii. This family of glycoproteins is conserved in streptococcal and staphylococcal species. A gene cluster coding for glycosyltransferases and accessory Sec proteins has been implicated in the protein glycosylation. A two-step glycosylation model is proposed. Two glycosyltransferases interact with each other and catalyse the first step of the protein glycosylation in the cytoplasm; the cross-talk between glycosylation-associated proteins and accessory Sec components mediates the second step of the protein glycosylation, an emerging mechanism for bacterial O-linked protein glycosylation. Dissecting the molecular mechanism of this conserved biosynthetic pathway offers opportunities to develop new therapeutic strategies targeting this previously unrecognized pathway, as serine-rich glycoproteins have been shown to play a role in bacterial pathogenesis.
Zhou
Meixian
M
Department of Pediatric Dentistry, UAB School of Dentistry, University of Alabama at Birmingham, Birmingham, AL 35294, USA.
Wu
Hui
H
Department of Pediatric Dentistry, UAB School of Dentistry, University of Alabama at Birmingham, Birmingham, AL 35294, USA.
D018829:Adhesins, Bacterial / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D000595:Amino Acid Sequence; D000818:Animals; D006023:Glycoproteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D006031:Glycosylation; D006801:Humans; D008969:Molecular Sequence Data; D005810:Multigene Family; D010802:Phylogeny; D012694:Serine / Q000378:metabolism*; D013290:Streptococcal Infections / Q000382:microbiology; D013291:Streptococcus / Q000737:chemistry / Q000145:classification / Q000235:genetics / Q000378:metabolism*
D018829:Adhesins, Bacterial; D006023:Glycoproteins; D012694:Serine