A DNA-SEQUENCE FOR POSITIONING CHROMATOSOMES

We have analysed the sequences of 280 chromatosomal DNA molecules. In approximately half the clones, a short DNA sequence of the preferred f orm NGGR is located at one, but not both, of the termini of the cloned DNA. We show that the clones lacking this signal possess a substantia lly stronger rotational positioning signal than those that contain it. These results indicate that the sequence organisation of chromatosoma l DNA is asymmetric with respect to the midpoint and imply that the se quence NGGR may play a direct role in positioning chromatosomes in con densed chromatin. (C) 1996 Academic Press Limited