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Identification of bacterial protein O-oligosaccharyltransferases and their glycoprotein substrates.

Schulz BL, Jen FE, Power PM, Jones CE, Fox KL, Ku SC, Blanchfield JT, Jennings MP - PLoS ONE (2013)

Bottom Line: We show that in the general glycosylation system of N. meningitidis, efficient glycosylation of additional protein substrates requires local structural similarity to the pilin acceptor site.For some Neisserial PglL substrates identified by sensitive analytical approaches, only a small fraction of the total protein pool is modified in the native organism, whereas others are completely glycosylated.Our results show that bacterial protein O-glycosylation is common, and that substrate selection in the general Neisserial system is dominated by recognition of structural homology.

View Article: PubMed Central - PubMed

Affiliation: School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland, Australia.

ABSTRACT
O-glycosylation of proteins in Neisseria meningitidis is catalyzed by PglL, which belongs to a protein family including WaaL O-antigen ligases. We developed two hidden Markov models that identify 31 novel candidate PglL homologs in diverse bacterial species, and describe several conserved sequence and structural features. Most of these genes are adjacent to possible novel target proteins for glycosylation. We show that in the general glycosylation system of N. meningitidis, efficient glycosylation of additional protein substrates requires local structural similarity to the pilin acceptor site. For some Neisserial PglL substrates identified by sensitive analytical approaches, only a small fraction of the total protein pool is modified in the native organism, whereas others are completely glycosylated. Our results show that bacterial protein O-glycosylation is common, and that substrate selection in the general Neisserial system is dominated by recognition of structural homology.

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Related in: MedlinePlus

Genomic arrangement of selected pglL genes.Schematic representation of the regions of the genome containing pglL genes in Neisseria meningitidis, Acinetobacter sp., Shigella flexneri and Ralstonia eutropha.
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pone-0062768-g002: Genomic arrangement of selected pglL genes.Schematic representation of the regions of the genome containing pglL genes in Neisseria meningitidis, Acinetobacter sp., Shigella flexneri and Ralstonia eutropha.

Mentions: Examination of the genome location of these pglL homologs revealed that in the majority of cases (21/31) they were immediately adjacent to or closely associated with a gene(s) encoding type IV pilin homologs (Table 1, Fig. 2). The close association of the pglL O-OTase with an obvious target glycoprotein in so many cases suggests that the HMM analysis identified both the glycosylation pathway and target acceptor protein. A further indication that the genes identified are PglL rather than WaaL homologs is that they are not located within LPS biosynthetic loci [24].


Identification of bacterial protein O-oligosaccharyltransferases and their glycoprotein substrates.

Schulz BL, Jen FE, Power PM, Jones CE, Fox KL, Ku SC, Blanchfield JT, Jennings MP - PLoS ONE (2013)

Genomic arrangement of selected pglL genes.Schematic representation of the regions of the genome containing pglL genes in Neisseria meningitidis, Acinetobacter sp., Shigella flexneri and Ralstonia eutropha.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3643930&req=5

pone-0062768-g002: Genomic arrangement of selected pglL genes.Schematic representation of the regions of the genome containing pglL genes in Neisseria meningitidis, Acinetobacter sp., Shigella flexneri and Ralstonia eutropha.
Mentions: Examination of the genome location of these pglL homologs revealed that in the majority of cases (21/31) they were immediately adjacent to or closely associated with a gene(s) encoding type IV pilin homologs (Table 1, Fig. 2). The close association of the pglL O-OTase with an obvious target glycoprotein in so many cases suggests that the HMM analysis identified both the glycosylation pathway and target acceptor protein. A further indication that the genes identified are PglL rather than WaaL homologs is that they are not located within LPS biosynthetic loci [24].

Bottom Line: We show that in the general glycosylation system of N. meningitidis, efficient glycosylation of additional protein substrates requires local structural similarity to the pilin acceptor site.For some Neisserial PglL substrates identified by sensitive analytical approaches, only a small fraction of the total protein pool is modified in the native organism, whereas others are completely glycosylated.Our results show that bacterial protein O-glycosylation is common, and that substrate selection in the general Neisserial system is dominated by recognition of structural homology.

View Article: PubMed Central - PubMed

Affiliation: School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland, Australia.

ABSTRACT
O-glycosylation of proteins in Neisseria meningitidis is catalyzed by PglL, which belongs to a protein family including WaaL O-antigen ligases. We developed two hidden Markov models that identify 31 novel candidate PglL homologs in diverse bacterial species, and describe several conserved sequence and structural features. Most of these genes are adjacent to possible novel target proteins for glycosylation. We show that in the general glycosylation system of N. meningitidis, efficient glycosylation of additional protein substrates requires local structural similarity to the pilin acceptor site. For some Neisserial PglL substrates identified by sensitive analytical approaches, only a small fraction of the total protein pool is modified in the native organism, whereas others are completely glycosylated. Our results show that bacterial protein O-glycosylation is common, and that substrate selection in the general Neisserial system is dominated by recognition of structural homology.

Show MeSH
Related in: MedlinePlus