AbA inhibits a yeast enzyme, inositol phosphorylceramide (IPC) synthase, which is expressed from the AUR1 gene (1, 2). Expression of a mutant gene, AUR1-C, in transformed yeast confers resistance to the drug. It is this gene that is used in Matchmaker Gold systems as a reporter for protein interactions.

Perfect Reporter for Yeast Two-Hybrid Studies

AbA selection virtually eliminates the high numbers of background colonies that often plague low-stringency primary screens that use nutritional markers alone (e.g. HIS3). Because AbA actually kills sensitive yeast cells, rather than merely retarding their growth, AbA-based selection greatly favors the growth and identification of genuinely positive clones. In general practice, a high percentage of clones that emerge from low-stringency primary screens using AbA selection alone, are subsequently verified on high-stringency secondary screens that select for all four Matchmaker Gold reporters (AUR1-C,HIS3, ADE2 and MEL1).