DOES A PROTOTYPE SCAFFOLD MATRIX-ATTACHED REGION (SAR SEQUENCE) AFFECT INTRINSIC NUCLEAR MATRIX ENDONUCLEASE SPECIFICITY

The nuclear matrix of plant cell nuclei has an intrinsic nuclease acti vity. The enzyme associated with the nuclear matrix converts superheli cal pCL and pTZ plasmid DNAs into their open circular form by introduc ing a single nick into one strand. The endonuclease reveals its specif icity only towards a super-coiled DNA form. The linearized plasmid DNA form is not recognized by the matrix nuclease. The SAR sequence that is characteristically present in nuclear matrix does not seem to affec t an endonuclease activity associated with the nuclear matrix.