The overall goal of the proposed research is to investigate specific mechanisms of transcription and regulation of transcription in eukaryotes through the characterization of trans-acting transcription factors in yeast. The SPT13 and SPT14 genes of Saccharomyces cerevisiae were identified by mutations that suppress Ty insertion mutations that inhibit adjacent gene expression. Based on both genetic and molecular experiments, SPT13 and SPT14 are candidates to act via the enhancer-like sequence in Ty (transposable) elements. The primary focus of the experiments described is the characterization of SPT13 and SPT14 in order to elucidate their mechanisms of action. In addition, the development of new genetic strategies for the direct and specific identification of genes encoding enhancer-binding factors are proposed.