The process in which a transformation is induced in the topological structure of a double-stranded DNA helix, resulting in a change in linking number.

The cellular synthesis of RNA on a template of DNA.

The cellular synthesis of RNA on a template of DNA.

Any process that results in a change in state or activity of a cell or an organism (in terms of movement, secretion, enzyme production, gene expression, etc.) as a result of a drug stimulus. A drug is a substance used in the diagnosis, treatment or prevention of a disease.

The process in which a transformation is induced in the topological structure of a double-stranded DNA helix, resulting in a change in linking number.

The process in which a transformation is induced in the topological structure of a double-stranded DNA helix, resulting in a change in linking number.

All of the contents of a cell excluding the plasma membrane and nucleus, but including other subcellular structures.

All of the contents of a cell excluding the plasma membrane and nucleus, but including other subcellular structures.

The part of the cytoplasm that does not contain organelles but which does contain other particulate matter, such as protein complexes.

A lipid bilayer along with all the proteins and protein complexes embedded in it an attached to it.

Complex that possesses DNA topoisomerase (ATP-hydrolyzing) activity.

The rigid or semi-rigid envelope lying outside the cell membrane of plant, fungal, most prokaryotic cells and some protozoan parasites, maintaining their shape and protecting them from osmotic lysis. In plants it is made of cellulose and, often, lignin; in fungi it is composed largely of polysaccharides; in bacteria it is composed of peptidoglycan; in protozoan parasites such as Giardia species, it's made of carbohydrates and proteins.

A semiautonomous, self replicating organelle that occurs in varying numbers, shapes, and sizes in the cytoplasm of virtually all eukaryotic cells. It is notably the site of tissue respiration.

The membrane surrounding a cell that separates the cell from its external environment. It consists of a phospholipid bilayer and associated proteins.

A chlorophyll-containing plastid with thylakoids organized into grana and frets, or stroma thylakoids, and embedded in a stroma.

A protein complex that interacts with the carboxy-terminal domain of the largest subunit of RNA polymerase II and plays an active role in transducing the signal from a transcription factor to the transcriptional machinery. The mediator complex is required for activation of transcription of most protein-coding genes, but can also act as a transcriptional corepressor. The Saccharomyces complex contains several identifiable subcomplexes: a head domain comprising Srb2, -4, and -5, Med6, -8, and -11, and Rox3 proteins; a middle domain comprising Med1, -4, and -7, Nut1 and -2, Cse2, Rgr1, Soh1, and Srb7 proteins; a tail consisting of Gal11p, Med2p, Pgd1p, and Sin4p; and a regulatory subcomplex comprising Ssn2, -3, and -8, and Srb8 proteins. Metazoan mediator complexes have similar modular structures and include homologs of yeast Srb and Med proteins.

The region of a chloroplast to which the DNA is confined.

Complex that possesses DNA topoisomerase (ATP-hydrolyzing) activity.