Small acidic peptides from wheat germ chromatin. II. Regulatory activity in specific transcription systems reconstituted in vitro.

A variety of evidence suggests that a family of chromatin peptides (CPs), characterized by 1000D molecular weight, a pH dependent association to DNA and a prevailing presence of acidic amino acids in their structure, is involved in the regulation of genes expression. Nevertheless their action mechanism is still unknown. In our in vitro specific RNA transcription systems the CPs affect the initiation and not the elongation. Furthermore they inhibit the RNA transcription by interaction with the DNA rather than with the enzyme. The phagic in vitro specific RNA transcription is less affected by CPs than the eubacteric system, suggesting a kind of selectivity for target DNA sequences involved in the initiation of transcription.