Isolation and Characterization of a Streptolydigin Resistant RNA Polymerase

Abstract

THE RNA polymerase of Escherichia coli consists of two small subunits α, two larger subunits β and β′, and one subunit σ which aids initiation¹. A question relevant to control of polymerase synthesis is whether genes coding for the various subunits are contiguous. Both rifampicin resistant RNA polymerase and streptovaricin resistant RNA polymerase map near the argH locus^2,3. Here I report that (a) streptolydigin inhibits chain elongation by E. coli RNA polymerase as was found by Siddhikol et al.⁴ for the polymerase of B. megaterium, (b) mutants altering the polymerase to streptolydigin resistance also map near argH, and (c) that, as is the case of rifampicin resistance^1,2, the “core” enzyme (the α₂ββ′ structure which itself possesses enzymatic activity) is modified in the resistant mutant.