Disease relevance of hlyD

• Examination of 55 clinical isolates of uropathogenic Escherichia coli producing the CNF1 toxin demonstrated that the cnf1 gene is systematically associated with a hly operon via a highly conserved hlyD-cnf1 intergenic region (igs, 943 bp) as shown in the J96 UPEC strain [1].
• One of the two E. coli secretion genes, hlyD, hybridized only with DNA from P. vulgaris and M. morganii, which produced cell-free hemolysis, but not with that from P. mirabilis, which showed only cell-associated activity [2].
• Using a dual-plasmid complementation system, we show that the alpha-hemolysin hlyB and hlyD transport determinants are sufficient to allow secretion and activation of a functional metalloprotease species from E. coli, as are the comparable protease secretion functions of Erwinia chrysanthemi [3].

High impact information on hlyD

• We aimed to establish an efficient Hly secretory expression system by random mutagenesis of hlyB and hlyD [4].
• We have identified gene products corresponding to hlyC, hlyA and hlyD encoded by the Escherichia coli haemolytic determinant 2001 of human origin cloned into the recombinant plasmid pLG570 [5].
• Finally, we were able to reconstitute the complete haemolysin system from three different plasmids encoding hlyC, hlyA and hlyB + hlyD, respectively [5].
• Subclones from the recombinant plasmid pLG570 carrying hlyD analysed in vitro and in minicells showed that this gene is transcribed from an independent promoter and encodes a 53 Kd polypeptide [6].
• Transposon mutagenesis leading to the synthesis of the expected truncated polypeptides was used to confirm the identity of the hlyD and the two hlyB products [6].

Biological context of hlyD

• Hemolysin plasmids were constructed with mutations in hlyB, hlyD, or both transport genes [7].

Anatomical context of hlyD

• Both mutants have entirely lost the haemolytic activity but the mutant haemolysins are still efficiently transported across both membranes when hlyB and hlyD are provided [8].

References