The Hd0053 gene of Haemophilus ducreyi encodes an α2,3-sialyltransferase

Haemophilus duereyi is a Gram-negative bacterium that causes chancroid, a sexually transmitted genital ulcer disease. Different lipooligosaccharide (LOS) structures have been identified from H. ducreyi strain 35000, including those sialylated glycoforms. Surface LOS of H. ducreyi is considered an important virulence factor that is involved in ulcer formation, cell adhesion, and invasion of host tissue. Gene Hd0686 of H. ducreyi, designated 1st (for lipooligosaccharide sialyltransferase), was identified to encode an alpha 2,3-sialyltransferase that is important for the formation of sialylated LOS. Here, we show that Hd0053 of H. ducreyi genomic strain 35000HP, the third member of the glycosyltransferase family 80 (GT80), also encodes an alpha 2,3-sialyltransferase that may be important for LOS sialylation. (c) 2007 Elsevier Inc. All rights reserved.