The quaternary structure of DNA-dependent RNA polymerase.
The crystals of RNA polymerase of T. thermophilus were examined by electron microscopic observation of the negatively stained and sectioned materials. Three types of crystals were observed: ordered aggregates (Type I), cylindrical duplei (Type II), and plane (Type III) forms. It was deduced mainly from sectioned images that Type I crystal is a precursor or a premature form of Type II crystal. The III corresponds to the flattened layer of type II. In Type II crystal the enzyme molecules are arranged in an orderly two-dimensional lattice and thus we could analyze the molecular structure by optical filtering of the negatively stained images. On the basis of these results, a quaternary structure is proposed for RNA polymerase.
D001419:Bacteria / Q000201:enzymology*; D055598:Chemical Phenomena; D002621:Chemistry; D003460:Crystallization; D003461:Crystallography; D012321:DNA-Directed RNA Polymerases; D046911:Macromolecular Substances; D008854:Microscopy, Electron; D008958:Models, Molecular
D046911:Macromolecular Substances; D012321:DNA-Directed RNA Polymerases