title: N-Methyl transferase of Streptomyces erythraeus that confers resistance to the macrolide-lincosamide-streptogramin B antibiotics: amino acid sequence and its homology to cognate R-factor enzymes from pathogenic bacilli and cocci.
abstract: The nucleotide sequence of a structural gene ermE for ribosomal RNA (rRNA) N6-amino adenine N-methyl transferase (NMT) of Streptomyces erythraeus, cloned by Thompson et al. [Gene 20 (1982) 51-62], has been determined. The NMT amino acid (aa) sequence deduced from the nucleotide sequence contains extensive homology to aa sequences of cognate NMTs specified by: (1) plasmid pE194 from Staphylococcus aureus, 30% G + C, ermC; (2) plasmid pAM77 from Streptococcus sanguis, 43% G + C; as well as to (3) a chromosomal determinant from Bacillus licheniformis 759, 46% G + C, ermD, cloned in a recombinant plasmid pBD90. These findings suggest that all four NMT structural genes could have evolved from a common progenitor sequence despite the wide range of % G + C of the erm genes reflecting their current respective hosts. Comparison of the four NMT sequences with respect to localized hydrophobicity averaged over a moving window of 11 aa indicates that the common features of localized hydrophobicity that characterize the C-terminal portion of the ermE and ermD proteins are distinguishable from a contrasting pattern of hydrophobicity that characterizes the ermC and pAM77-coded proteins.
mesh_terms: D000595:Amino Acid Sequence; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001407:Bacillus / Q000201:enzymology / Q000235:genetics; D001482:Base Composition; D001483:Base Sequence; D003062:Codon; D055231:Lincosamides; D018942:Macrolides; D008780:Methyltransferases / Q000235:genetics*; D011487:Protein Conformation; D011815:R Factors; D012689:Sequence Homology, Nucleic Acid; D012995:Solubility; D013302:Streptomyces / Q000201:enzymology* / Q000235:genetics; D014769:Virginiamycin / Q000494:pharmacology
chemical_list: D000900:Anti-Bacterial Agents; D003062:Codon; D055231:Lincosamides; D018942:Macrolides; D014769:Virginiamycin; D008780:Methyltransferases