Identification of a distinct, cryptic heparosan synthase from Pasteurella multocida types A, D, and F

J Bacteriol. 2004 Dec;186(24):8529-32. doi: 10.1128/JB.186.24.8529-8532.2004.


The extracellular polysaccharide capsules of Pasteurella multocida types A, D, and F are composed of hyaluronan, N-acetylheparosan (heparosan or unsulfated, unepimerized heparin), and unsulfated chondroitin, respectively. Previously, a type D heparosan synthase, a glycosyltransferase that forms the repeating disaccharide heparosan backbone, was identified. Here, a approximately 73% identical gene product that is encoded outside of the capsule biosynthesis locus was also shown to be a functional heparosan synthase. Unlike PmHS1, the PmHS2 enzyme was not stimulated greatly by the addition of an exogenous polymer acceptor and yielded smaller- molecular-weight-product size distributions. Virtually identical hssB genes are found in most type A, D, and F isolates. The occurrence of multiple polysaccharide synthases in a single strain invokes the potential for capsular variation.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Bacterial Capsules
  • Bacterial Proteins / chemistry
  • Bacterial Proteins / classification
  • Bacterial Proteins / genetics
  • Bacterial Proteins / metabolism
  • Glycosyltransferases* / chemistry
  • Glycosyltransferases* / classification
  • Glycosyltransferases* / genetics
  • Glycosyltransferases* / metabolism
  • Molecular Sequence Data
  • Pasteurella multocida / classification
  • Pasteurella multocida / enzymology*
  • Pasteurella multocida / genetics
  • Recombinant Proteins / genetics
  • Recombinant Proteins / metabolism
  • Sequence Analysis, DNA


  • Bacterial Proteins
  • Recombinant Proteins
  • Glycosyltransferases
  • heparosan synthase

Associated data

  • GENBANK/AY292199
  • GENBANK/AY292200