Increasing Yields From Combinatorial Libraries

Period of Performance: 09/30/1998 - 09/29/1999


Phase 1 STTR

Recipient Firm

Chromaxome Corporation
San Diego, CA 92121
Principal Investigator


DESCRIPTION: Combinatorial biology is an emerging technology for the discovery of novel medically useful bacterial natural products. The absA signal transduction pathway is a global negative regulator of antibiotic synthesis in Streptomyces coelicolor: a null mutation in this locus produces premature over-expression of all antibiotics (up to seven-fold) in S. coelicolor. A second phenotype associated the absA null mutations is a reduction in transformation efficiency when compared to wild-type S. coelicolor. The phase I proposal will initially assess whether the absA signal transduction pathway is also a global negative regulator of the endogenous antibiotic actinorhodin and undecylprodigiosin in Streptomyces lividans TK64, a strain which is undergoing development as a expression host for combinatorial experiments, and whether directed mutations to the S. lividans absA locus will increase the efficiency of screens for novel biologically-useful natural products from combinatorial libraries. Also preliminary studies will assess whether it is possible to genetically separate the two phenotypes associated with the absA deletion to create a strain that over-produces antibiotics without a reduction in transformation efficiency. This work will set the stage for the phase II proposal: development of an optimized S. lividans expression host. If manipulation of absA causes overproduction of antibiotics from combinatorial libraries this enhancement will greatly facilitate the rapid and efficient assaying of clones that potentially encode useful biosynthetic pathways both by reducing the incubation time until maximum expression is achieved and by increasing the chances of detecting poorly expressed antibiotics. PROPOSED COMMERCIAL APPLICATION: NOT AVAILABLE