Cloning of an aminoglycoside-resistance-encoding gene, kamC, from Saccharopolyspora hirsuta: comparison with kamB from Streptomyces tenebrarius.

An aminoglycoside-resistance-encoding gene (kamC) has been isolated from the sporaricin producer, Saccharopolyspora (Sac.) hirsuta, and expressed both in Streptomyces lividans and Escherichia coli. The pattern of resistance conferred by this gene was identical to that given by another gene (kamB) previously isolated from Streptomyces tenebrarius. In accordance with the known action of the kamB product, the Sac, hirsuta determinant also encodes a methyltransferase that modifies 16S rRNA, thereby rendering ribosomes refractory to certain aminoglycosides. The nucleotide sequences of both genes have been determined and comparison of the deduced amino acid sequences reveals a high degree of similarity.