Biomaterial Database

Yeast mitochondrial RNA polymerase. Purification and properties of the catalytic subunit. 1986

J L Kelly, and I R Lehman

An RNA polymerase was purified 6500-fold to near homogeneity from a whole cell extract of Saccharomyces cerevisiae. The purified enzyme consists of a single 145,000-dalton polypeptide. By subcellular fractionation, the enzyme was localized to the mitochondria. The RNA polymerase activity is alpha-amanitin- and rifampicin-resistant. With single-stranded DNA templates, the enzyme catalyzes the synthesis of polyribonucleotide chains with lengths ranging from less than 10 to greater than 100 residues. It is inactive with double-stranded DNA. Specific antisera inhibit the RNA polymerase activity and recognize the 145,000-dalton polypeptide. The antisera relate this enzyme to previously described yeast mitochondrial RNA polymerase preparations capable of initiation of transcription at mitochondrial promoter sequences (Winkley, C. S., Keller, M. J., and Jaehning, J. A. (1985) J. Biol. Chem. 260, 14214-14223). It therefore appears that the enzyme is a subunit of the yeast mitochondrial RNA polymerase.

UI	MeSH Term	Description	Entries
D007106	Immune Sera	Serum that contains antibodies. It is obtained from an animal that has been immunized either by ANTIGEN injection or infection with microorganisms containing the antigen.	Antisera,Immune Serums,Sera, Immune,Serums, Immune
D008928	Mitochondria	Semiautonomous, self-reproducing organelles that occur in the cytoplasm of all cells of most, but not all, eukaryotes. Each mitochondrion is surrounded by a double limiting membrane. The inner membrane is highly invaginated, and its projections are called cristae. Mitochondria are the sites of the reactions of oxidative phosphorylation, which result in the formation of ATP. They contain distinctive RIBOSOMES, transfer RNAs (RNA, TRANSFER); AMINO ACYL T RNA SYNTHETASES; and elongation and termination factors. Mitochondria depend upon genes within the nucleus of the cells in which they reside for many essential messenger RNAs (RNA, MESSENGER). Mitochondria are believed to have arisen from aerobic bacteria that established a symbiotic relationship with primitive protoeukaryotes. (King & Stansfield, A Dictionary of Genetics, 4th ed)	Mitochondrial Contraction,Mitochondrion,Contraction, Mitochondrial,Contractions, Mitochondrial,Mitochondrial Contractions
D011089	Polydeoxyribonucleotides	A group of 13 or more deoxyribonucleotides in which the phosphate residues of each deoxyribonucleotide act as bridges in forming diester linkages between the deoxyribose moieties.	Polydeoxyribonucleotide
D011131	Polyribonucleotides	A group of 13 or more ribonucleotides in which the phosphate residues of each ribonucleotide act as bridges in forming diester linkages between the ribose moieties.
D011232	Chemical Precipitation	The formation of a solid in a solution as a result of a chemical reaction or the aggregation of soluble substances into complexes large enough to fall out of solution.	Precipitation, Chemical
D002499	Centrifugation, Density Gradient	Separation of particles according to density by employing a gradient of varying densities. At equilibrium each particle settles in the gradient at a point equal to its density. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)	Centrifugations, Density Gradient,Density Gradient Centrifugation,Density Gradient Centrifugations,Gradient Centrifugation, Density,Gradient Centrifugations, Density
D002627	Chemistry, Physical	The study of CHEMICAL PHENOMENA and processes in terms of the underlying PHYSICAL PHENOMENA and processes.	Physical Chemistry,Chemistries, Physical,Physical Chemistries
D002845	Chromatography	Techniques used to separate mixtures of substances based on differences in the relative affinities of the substances for mobile and stationary phases. A mobile phase (fluid or gas) passes through a column containing a stationary phase of porous solid or liquid coated on a solid support. Usage is both analytical for small amounts and preparative for bulk amounts.	Chromatographies
D004256	DNA Polymerase I	A DNA-dependent DNA polymerase characterized in prokaryotes and may be present in higher organisms. It has both 3'-5' and 5'-3' exonuclease activity, but cannot use native double-stranded DNA as template-primer. It is not inhibited by sulfhydryl reagents and is active in both DNA synthesis and repair.	DNA Polymerase alpha,DNA-Dependent DNA Polymerase I,Klenow Fragment,DNA Pol I,DNA Dependent DNA Polymerase I,Polymerase alpha, DNA
D004277	DNA, Single-Stranded	A single chain of deoxyribonucleotides that occurs in some bacteria and viruses. It usually exists as a covalently closed circle.	Single-Stranded DNA,DNA, Single Stranded,Single Stranded DNA