[Localization of mutation leading to resistance of E. coli RNA polymerase to the antibiotic streptolydigin in the gene rpoB coding for the beta-subunit of the enzyme].

For the first time a mutation of streptolydigin resistance was localized. It was discovered to be a double substitution, namely Gly544----Asp, Phe545----Ser, in the region where most rif-r mutations are located. One may suppose that this region takes part in the formation of both elongation NTP binding site, blocked by streptolydigin, and RNA chain binding and translocation site that is blocked by rifampicin.