Analysis of the self-defense gene (fmrO) of a fortimicin A (astromicin) producer, Micromonospora olivasterospora: comparison with other aminoglycoside-resistance-encoding genes

Gene. 1993 May 15;127(1):63-9. doi: 10.1016/0378-1119(93)90617-c.


The nucleotide (nt) sequence of a 3409-bp PvuII fragment carrying the self-defense gene (fmrO) of a fortimicin A (FmA; astromicin) producer, Micromonospora olivasterospora, was determined; four open reading frames (ORFs) exist in this region. Expression analysis of fmrO using the lac promoter in Escherichia coli revealed that ORF-3 encodes fmrO. ORF-1 was considered to encode a FmKH epimerase (fms11). ORF-2, ORF-3 and ORF-4 seemed to form an operon. No homology was detected between fmrO and the resistance-encoding gene fmrT of Streptomyces tenjimariensis, a producer of the Fm-group antibiotic, istamycin. Gene organization around the fmr genes differed considerably between M. olivasterospora and S. tenjimariensis. The deduced amino acid sequence of fmrO showed an identity of 30.8% to grmA of M. purpurea and 35.8% to grmB of M. rosea, respectively, suggesting that fmrO encodes a 16S rRNA methyltransferase. We found in M. purpurea a novel resistance gene distinct from grmA and highly similar to fmrO which conferred a resistance phenotype similar to that of fmrO. These results suggest that fmrO of M. olivasterospora and the two resistance-encoding genes of M. purpurea were derived from a common ancestral gene.

MeSH terms

  • Amino Acid Sequence
  • Aminoglycosides*
  • Anti-Bacterial Agents / pharmacology*
  • Base Sequence
  • Blotting, Southern
  • Cloning, Molecular
  • DNA, Bacterial
  • Drug Resistance, Microbial / genetics
  • Genes, Bacterial*
  • Humans
  • Infant, Newborn
  • Methyltransferases / genetics
  • Micromonospora / genetics*
  • Molecular Sequence Data
  • Open Reading Frames
  • Restriction Mapping
  • Sequence Homology, Amino Acid


  • Aminoglycosides
  • Anti-Bacterial Agents
  • DNA, Bacterial
  • fortimicin A
  • Methyltransferases

Associated data

  • GENBANK/D13171
  • GENBANK/D13184
  • GENBANK/L03653
  • GENBANK/L03654
  • GENBANK/L07632
  • GENBANK/M97806
  • GENBANK/S60629
  • GENBANK/S60630
  • GENBANK/X54209
  • GENBANK/X67283