A variety of novel lipid A structures obtained from Francisella tularensis live vaccine strain.

F. tularensis is a Gram-negative coccobacillus that causes tularemia. Its LPS has nominal biological activity.

Deciphering the unusual acylation pattern of Helicobacter pylori lipid A.

The synthesis of "typical" hexa-acylated lipid A occurs via a nine-step enzymatic pathway, which is generally well conserved throughout all gram-negative bacteria. One exception to the rule is Helicobacter pylori, which has only eight homologs to the nine lipid A biosynthetic enzymes. The discrepancy occurs toward the end of the pathway, with H.