A repeated decapeptide motif in the C-terminal domain of the ribosomal RNA methyltransferase from the erythromycin producer Saccharopolyspora erythraea.
Re-analysis of the primary structure of the ribosomal RNA N-methyltransferase that confers self-resistance on the erythromycin-producing bacterium Saccharopolyspora erythraea has confirmed the presence of a C-terminal domain containing extensive repeat sequences. Nine tandem repeats can be discerned, with a decapeptide consensus sequence GGRx(H/R)GDRRT, although no single residue is wholly invariant. This highly polar, potentially flexible domain, which is predicted to adopt either a random coil or a structure with beta turns, has a counterpart in the erythromycin methyltransferase of an erythromycin-producing species of Arthrobacter. It also significantly resembles a portion of the C-terminal region of the eukaryotic protein nucleolin, which is unusually rich in dimethylarginine and glycine, and which is also predicted to behave as a random coil in solution. This resemblance, despite the very different roles of these proteins in ribosome biogenesis, strengthens the idea that in both rRNA methyltransferases and nucleolin these C-terminal sequences might contribute to rRNA binding.
Dhillon
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N
Department of Biochemistry, University of Cambridge, England.
Leadlay
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PF
D000595:Amino Acid Sequence; D001483:Base Sequence; D001330:Electronic Data Processing; D004917:Erythromycin / Q000378:metabolism*; D008780:Methyltransferases / Q000235:genetics*; D008969:Molecular Sequence Data; D011487:Protein Conformation; D012091:Repetitive Sequences, Nucleic Acid; D013302:Streptomyces / Q000201:enzymology / Q000235:genetics*; D013329:Structure-Activity Relationship
D004917:Erythromycin; D008780:Methyltransferases; C035181:rRNA (adenosine-O-2'-)methyltransferase