The human genome contains hundreds of genes coding for finger proteins of the Krüppel type

Our aim was to identify new human proteins with potential DNA binding activity, related to the Krüppel protein which regulates Drosophila segmentation. We screened a human placenta cDNA library and a human genomic DNA library with a synthetic oligonucleotide probe corresponding to the H/C link region that connects finger loops in the multifingered Krüppel protein. We found more than 100 different mRNAs encoding Krüppel multifingered proteins in the human placenta. In the whole human genome, the number of genes encoding such proteins reaches about 300. Sequence analysis of 14 cloned cDNAs indicated that they code for at least nine undescribed human finger proteins. The sequences of the 106 finger repeats present in these nine proteins are highly homologous. Most of the variability lies in a limited number of positions located in their postulated alpha-helical structure, and therefore could be implicated in their DNA-binding specificity.