  A chemical kinetic model of the elongation dynamics of RNA polymerase along a
DNA sequence is introduced. The proposed model governs the discrete movement of
the RNA polymerase along a DNA template, with no consideration given to elastic
effects. The model's novel concept is a ``look-ahead'' feature, in which
nucleotides bind reversibly to the DNA prior to being incorporated covalently
into the nascent RNA chain. Results are presented for specific DNA sequences
that have been used in single-molecule experiments of the random walk of RNA
polymerase along DNA. By replicating the data analysis algorithm from the
experimental procedure, the model produces velocity histograms, enabling direct
comparison with these published results.
