Structural insights into the function of aminoglycoside-resistance A1408 16S rRNA methyltransferases from antibiotic-producing and human pathogenic bacteria.

ABSTRACT: X-ray crystal structures were determined of the broad-spectrum aminoglycoside-resistance A1408 16S rRNA methyltransferases KamB and NpmA, from the aminoglycoside-producer Streptoalloteichus tenebrarius and human pathogenic Escherichia coli, respectively. Consistent with their common function, both are Class I methyltransferases with additional highly conserved structural motifs that embellish the core SAM-binding fold. In overall structure, the A1408 rRNA methyltransferase were found to be most similar to a second family of Class I methyltransferases of distinct substrate specificity (m(7)G46 tRNA). Critical residues for A1408 rRNA methyltransferase activity were experimentally defined using protein mutagenesis and bacterial growth assays with kanamycin. Essential residues for SAM coenzyme

SUBMITTER: Macmaster R 

PROVIDER: S-EPMC2995053 | biostudies-literature | 2010 Nov

REPOSITORIES: biostudies-literature