Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2002-4-22
pubmed:databankReference
pubmed:abstractText
Bacteria tune the function of their ribosomes by methylating specific rRNA nucleotides. Nucleotide G745 in Escherichia coli 23S rRNA is methylated by the methyltransferase enzyme RrmA, whereas in Streptomyces fradiae, the neighbouring nucleotide G748 is methylated by the enzyme TlrB. Both nucleotides line the peptide exit channel of the ribosome at the binding site of macrolide, lincosamide and streptogramin B antibiotics. Resistance to the macrolide tylosin, which is produced by S. fradiae, is conferred by methylation of G748. RrmA and TlrB are homologues (29% identical), and a database search against all presently available sequences revealed a further two dozen homologues from a wide variety of Bacteria. No homologues were found among the Archaea or Eukarya. The bacterial sequences adhere to the species phylogeny and segregate into two groups, in which the Gram-negative sequences align with RrmA and the Gram-positives with TlrB. Consistently, in more than 20 species tested, the distribution of methylation in the Gram-negative rRNAs (methylated at G745) and the Gram-positives (methylated at G748) perfectly matches the bacterial phylogeny. Cloning and expression of representative methyltransferase genes showed that this specificity of methylation is determined solely by the methyltransferase enzyme and is independent of the origin of the rRNA substrate. This is the first case in which the position of an RNA methylation defines a sharp division between the Gram-negative and Gram-positive bacteria. Given the specificities and distribution of these methyltransferases, we propose a change in the nomenclature of RrmA to RlmAI (rRNA large subunit methyltransferase) and of TlrB to RlmAII.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0950-382X
pubmed:author
pubmed:issnType
Print
pubmed:volume
44
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
195-204
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2002
pubmed:articleTitle
Methylation at nucleotide G745 or G748 in 23S rRNA distinguishes Gram-negative from Gram-positive bacteria.
pubmed:affiliation
Department of Biochemistry and Molecular Biology, University of Southern Denmark, DK-5230 Odense M, Denmark.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, Non-U.S. Gov't