Tagetitoxin, a chlorosis-inducing phytotoxin produced by Pseudomonas syringae pv. tagetis, inhibits RNA synthesis directed by chloroplast RNA polymerase. In isolated chloroplasts, tagetitoxin quickly and specifically reduced the incorporation of [3H]uridine into RNA. When it was added to transcriptionally active chloroplast protein extracts, the toxin directly inhibited incorporation of [32P]UT...

Unlike DNA polymerases, an RNA polymerase must initiate transcription de novo, that is binding of the initiating (+1) nucleoside triphosphate must be achieved without benefit of the cooperative binding energetics of an associated primer. Since a single Watson-Crick base pair is not stable in solution, RNA polymerases might be expected to provide additional stabilizing interactions to facilitate...

Infectious vesicular stomatitis virus (VSV), the prototypic nonsegmented negative-strand RNA virus, was recovered from a full-length cDNA clone of the viral genome. Bacteriophage T7 RNA polymerase expressed from a recombinant vaccinia virus was used to drive the synthesis of a genome-length positive-sense transcript of VSV from a cDNA clone in baby hamster kidney cells that were simultaneously ...

T7 RNA polymerase (T7 RNAP) is an enzyme that utilizes ribonucleotides to synthesize the nascent RNA chain in a template-dependent manner. In this work we have studied the interaction of T7 RNAP with cibacron blue, an anthraquinone monochlorotriazine dye, and its effect on the function of the enzyme. T7 RNAP binds to the dye in a bi-phasic manner. The first phase of the binding is characterized...

O(6)-Methylguanine (O(6)-meG) is a major mutagenic, carcinogenic and cytotoxic DNA adduct produced by various endogenous and exogenous methylating agents. We report the results of transcription past a site-specifically modified O(6)-meG DNA template by bacteriophage T7 RNA polymerase and human RNA polymerase II. These data show that O(6)-meG partially blocks T7 RNA polymerase and human RNA poly...