The biosynthetic origin of ribofuranose in bacterial polysaccharides.
Nat Chem Biol
; 18(5): 530-537, 2022 05.
Article
em En
| MEDLINE
| ID: mdl-35393575
ABSTRACT
Bacterial surface polysaccharides are assembled by glycosyltransferase enzymes that typically use sugar nucleotide or polyprenyl-monophosphosugar activated donors. Characterized representatives exist for many monosaccharides but neither the donor nor the corresponding glycosyltransferases have been definitively identified for ribofuranose residues found in some polysaccharides. Klebsiella pneumoniae O-antigen polysaccharides provided prototypes to identify dual-domain ribofuranosyltransferase proteins catalyzing a two-step reaction sequence. Phosphoribosyl-5-phospho-D-ribosyl-α-1-diphosphate serves as the donor for a glycan acceptor-specific phosphoribosyl transferase (gPRT), and a more promiscuous phosphoribosyl-phosphatase (PRP) then removes the residual 5'-phosphate. The 2.5-Å resolution crystal structure of a dual-domain ribofuranosyltransferase ortholog from Thermobacillus composti revealed a PRP domain that conserves many features of the phosphatase members of the haloacid dehalogenase family, and a gPRT domain that diverges substantially from all previously characterized phosphoribosyl transferases. The gPRT represents a new glycosyltransferase fold conserved in the most abundant ribofuranosyltransferase family.
Texto completo:
1
Coleções:
01-internacional
Temas:
Geral
Base de dados:
MEDLINE
Assunto principal:
Polissacarídeos Bacterianos
/
Glicosiltransferases
Idioma:
En
Revista:
Nat Chem Biol
Assunto da revista:
BIOLOGIA
/
QUIMICA
Ano de publicação:
2022
Tipo de documento:
Article
País de afiliação:
Canadá