Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
16
pubmed:dateCreated
2006-4-17
pubmed:abstractText
Nearly two dozen microbial pathogens have surface polysaccharides or lipo-oligosaccharides that contain sialic acid (Sia), and several Sia-dependent virulence mechanisms are known to enhance bacterial survival or result in host tissue injury. Some pathogens are also known to O-acetylate their Sias, although the role of this modification in pathogenesis remains unclear. We report that neuD, a gene located within the Group B Streptococcus (GBS) Sia biosynthetic gene cluster, encodes a Sia O-acetyltransferase that is itself required for capsular polysaccharide (CPS) sialylation. Homology modeling and site-directed mutagenesis identified Lys-123 as a critical residue for Sia O-acetyltransferase activity. Moreover, a single nucleotide polymorphism in neuD can determine whether GBS displays a "high" or "low" Sia O-acetylation phenotype. Complementation analysis revealed that Escherichia coli K1 NeuD also functions as a Sia O-acetyltransferase in GBS. In fact, NeuD homologs are commonly found within Sia biosynthetic gene clusters. A bioinformatic approach identified 18 bacterial species with a Sia biosynthetic gene cluster that included neuD. Included in this list are the sialylated human pathogens Legionella pneumophila, Vibrio parahemeolyticus, Pseudomonas aeruginosa, and Campylobacter jejuni, as well as an additional 12 bacterial species never before analyzed for Sia expression. Phylogenetic analysis shows that NeuD homologs of sialylated pathogens share a common evolutionary lineage distinct from the poly-Sia O-acetyltransferase of E. coli K1. These studies define a molecular genetic approach for the selective elimination of GBS Sia O-acetylation without concurrent loss of sialylation, a key to further studies addressing the role(s) of this modification in bacterial virulence.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
21
pubmed:volume
281
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
11186-92
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed-meshheading:16490781-Acetyltransferases, pubmed-meshheading:16490781-Alleles, pubmed-meshheading:16490781-Amino Acid Sequence, pubmed-meshheading:16490781-Chromatography, High Pressure Liquid, pubmed-meshheading:16490781-Computational Biology, pubmed-meshheading:16490781-DNA, pubmed-meshheading:16490781-Escherichia coli, pubmed-meshheading:16490781-Escherichia coli Proteins, pubmed-meshheading:16490781-Gene Expression Regulation, Bacterial, pubmed-meshheading:16490781-Genetic Complementation Test, pubmed-meshheading:16490781-Models, Chemical, pubmed-meshheading:16490781-Models, Molecular, pubmed-meshheading:16490781-Molecular Sequence Data, pubmed-meshheading:16490781-Multigene Family, pubmed-meshheading:16490781-Mutagenesis, Site-Directed, pubmed-meshheading:16490781-Mutation, pubmed-meshheading:16490781-N-Acetylneuraminic Acid, pubmed-meshheading:16490781-Phylogeny, pubmed-meshheading:16490781-Polymerase Chain Reaction, pubmed-meshheading:16490781-Polymorphism, Genetic, pubmed-meshheading:16490781-Polymorphism, Single Nucleotide, pubmed-meshheading:16490781-Protein Conformation, pubmed-meshheading:16490781-Sequence Homology, Amino Acid, pubmed-meshheading:16490781-Software, pubmed-meshheading:16490781-Streptococcus agalactiae, pubmed-meshheading:16490781-Virulence
pubmed:year
2006
pubmed:articleTitle
The group B streptococcal sialic acid O-acetyltransferase is encoded by neuD, a conserved component of bacterial sialic acid biosynthetic gene clusters.
pubmed:affiliation
Division of Biological Sciences, University of California San Diego, 92093-0687, USA.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't, Research Support, N.I.H., Extramural