Abstract: Provided are compositions and methods for cleaving a DNA sequence in a cell. The methods involve comprising introducing into a cell a recombinant vector containing a clustered regularly interspaced short palindromic repeats (CRISPR) system. The system includes a CRISPR RNA (crRNA) targeted to a DNA sequence in the cell that is operatively linked to a promoter; and CRISPR-associated enzymes (Cas) 10, Cas6, and at least one Csm protein. The Cas 10 cleaves the DNA sequence only during transcription of the DNA sequence that is operatively linked to the promoter. Also provided are recombinant vectors for modifying cells, cells that contain the recombinant vectors and modifications introduced by them, and kits that include the modified vectors.

Abstract: Provided are compositions and methods for cleaving a DNA sequence in a cell. The methods involve comprising introducing into a cell a recombinant vector containing a clustered regularly interspaced short palindromic repeats (CRISPR) system. The system includes a CRISPR RNA (crRNA) targeted to a DNA sequence in the cell that is operatively linked to a promoter; and CRISPR-associated enzymes (Cas) 10, Cas6, and at least one Csm protein. The Cas 10 cleaves the DNA sequence only during transcription of the DNA sequence that is operatively linked to the promoter. Also provided are recombinant vectors for modifying cells, cells that contain the recombinant vectors and modifications introduced by them, and kits that include the modified vectors.

Abstract: A novel interstitial collagenase is disclosed which acts as an ATP-independent molecular motor driven by the proteolysis of substrate collagen. Also disclosed is a method of reacting interstitial collagenase with a collagen fibril to encounter multiple cleavage sites without substantial dissociation of said interstitial collagenase and thereby act as a molecular motor driven by the proteolysis of substrate collagen. The invention thus is useful as a research tool in the tissue remodeling and cell-matrix interaction. The invention also has significant utility in the screening and development of inhibitors of interstitial collagenase and as a research tool for evaluating the activity and effect of drug candidates.