Member database | PROSITE patterns |
PROSITE patterns type | conserved site |
Short name | RRNA_A_DIMETH |
Description
A number of enzymes responsible for the dimethylation of adenosines in
ribosomal RNAs (EC 2.1.1.48) have been found
[1] to be evolutionary related.
These enzymes are:
- Bacterial 16S rRNA dimethylase (gene ksgA), which acts in the biogenesis
of ribosomes by catalyzing the dimethylation of two adjacent adenosines in
the loop of a conserved hairpin near the 3'-end of 16S rRNA. Inactivation
of ksgA leads to resistance to the aminoglycoside antibiotic kasugamycin.
- Yeast 18S rRNA dimethylase (gene DIM1), which is functionally similar to
ksgA and that dimethylates twin adenosines in the 3'-end of 18S rRNA.
- Bacterial 'erm' methylases. These enzymes confer resistance to macrolide-
lincosamide-streptogramin B (MLS) antibiotics - such as erythromycin - by
dimethylating the adenine residue at position 2058 of 23S rRNA thus
resulting in a reduced affinity between ribosomes and the MLS antibiotics.
- Caenorhabditis elegans hypothetical protein EO2H1.1.
The best conserved region in these enzymes is located in the N-terminal
section and corresponds to a region that is probably involved in S-adenosyl
methionine (SAM) binding.
References
1.The DIM1 gene responsible for the conserved m6(2)Am6(2)A dimethylation in the 3'-terminal loop of 18 S rRNA is essential in yeast. Lafontaine D, Delcour J, Glasser AL, Desgres J, Vandenhaute J. J. Mol. Biol. 241, 492-7, (1994). View articlePMID: 8064863