Three cDNAs encoding ribosomal RNA gene promoter binding protein have
been cloned from yeast lambda gt11 cDNA library by plaque southwestern
hybridization technique. All proteins from the selected clones could
selectively bind to promoter and enhancer sequences of 35 S ribosomal
RNA (rRNA) gene. These proteins did not show any affinity with interna
l DNA sequences of tetracycline resistance structural gene. The insert
ed cDNAs of these clones were found to have the same DNA sequences at
5' end, but have various lengths of DNA due to truncation at the 3' re
gion.