The Stirred Flow Reactor: Base Analog Incorporation in DNA Replication and Transcription

We compare base analog incorporation in two template processes that are carried out in a stirred flow reactor at the steady state. In calf thymus DNA transcription with RNA polymerase we use inosine as a base analog to guanine and determine its percent incorporation P(I) into RNA. P(I) is found to be independent of average residence time in the stirred fow reactor and dependent on the initial concentration of ITP relative to GTP in both open and closed systems. In poly[d(A‐T)] replication with DNA polymerase I we use 2‐aminopurine as a base analog for adenine. By contrast, the percent incorporation of 2‐aminopurine is strongly dependent on average residence time in the stirred flow reactor besides showing a dependency on initial concentration of 2‐aminopurine (n2 h2 dATP). Thus the base analog incorporation probability may be affected by the residence time in replication but not in transcription. This difference is due to the effect of kinetic nonlinearities in poly[d(A‐T)] replication as carried out under present concentration conditions.