Difference between revisions of "Part:BBa K1045003"

Revision as of 17:23, 28 October 2013

Diadenylate cyclase domain of Listeria monocytogenes cdaA (DacA)

The severe threat caused by bacteria which are resistant to conventional antibiotic drugs and the appearance of even multi-resistant strains demonstrates the urgent need for the discovery of new antibacterial substance classes. Cyclic di-AMP was discovered to be an essential signal molecule in Gram-positive bacteria including the pathogenic species Streptococcus pneumoniae, Staphylococcus aureus and Listeria monocytogenes. Both, loss and overproduction of c-di-AMP have detrimental effects on cell growth, cell wall synthesis, and propagation. Thus, the diadenylate cyclase (DAC) which catalyses the condensation reaction of two ATP molecules to c-di-AMP is the key factor for signal molecule production and maintenance of c-di-AMP homeostasis. We are convinced that the DAC is a very promising target for the development of highly specific antibiotic substances which exclusively act on Gram-positive bacteria and are not harmful to Gram-negative ones, including the gut bacterium Escherichia coli as well as humans. Here, we introduce a truncated but functional DAC which localizes to the cytosol and can easily be purified.
Furthermore, the protein was crystallized and the X-ray diffraction pattern obtained. This enabled the determination of the 3D-structure of DacA by Molecular Replacement using the similar diadenylate cyclase DisA from B. subtilis.

Fig. 1. c-di-AMP production and degradation. c-di-AMP is produced from two molecules of ATP by DACs and degraded to pApA by phosphodiasterases. (Edited from Corrigan and Gründling, 2013)

The part BBa_K1045003 described here, covers the amino acids 100 to 273 of the full length coding sequence of CdaA. For a precise description of this part, please vistit the experience page!

Sequence and Features