Structure and function of the bacteriophage T7 RNA polymerase (or, the virtues of simplicity).

A consideration of the properties of a number of mutants of T7 RNA polymerase, together with emerging structural information (Sousa et al., 1993) allows an interpretation of the the mechanics of transcription by this relatively simple RNA polymerase. Evidence indicating features in common with other nucleotide polymerases (such as DNA polymerases and reverse transcriptases) is reviewed.