Modomics - A Database of RNA Modifications

Full name:	Dimethyladenosine transferase
Synonym:	Dim1
GI:	1169344
Orf:	YPL266W
COG:	COG0030
UniProt:	P41819
Structures:	\| \|
Complex:
Enzyme type:	methyltransferase
Position of modification - modification:	s:1779(1518) - m6,6A s:1780(1519) - m6,6A

Comments:

SceRsmA (formerly Dim1p) dimethylates two adjacent A (positions 1779 and 1780; 1518 and 1519 in E. coli numberings) in the loop of a conserved hairpin h45 near the 3′-end of 18S rRNA. AdoMet is the methyl group donor. RsmA can bind on naked rRNA but the target bases cannot be methylated before a subset of ribosomal proteins have bound. Dim2p could be a cofactor. Bacterial RsmA (KsgA) is the ortholog of yeast RsmA (Dim1p). They belong to the erm family of methyltransferases responsible for erythromycin resistance. RsmA homologs exists also Archaea. Notice, the acronym RsmA has also been used for for Regulator of Secondary Metabolism A, a protein not related to the RNA small subunit Methyltransferase.

Protein sequence:

MGKAAKKKYSGATSSKQVSAEKHLSSVFKFNTDLGQHILKNPLVAQGIVDKAQIRPSDVVLEVGPGTGNLTVRILEQAKNVVAVEMDPRMAAELTKRVRG
TPVEKKLEIMLGDFMKTELPYFDICISNTPYQISSPLVFKLINQPRPPRVSILMFQREFALRLLARPGDSLYCRLSANVQMWANVTHIMKVGKNNFRPPP
QVESSVVRLEIKNPRPQVDYNEWDGLLRIVFVRKNRTISAGFKSTTVMDILEKNYKTFLAMNNEMVDDTKGSMHDVVKEKIDTVLKETDLGDKRAGKCDQ
NDFLRLLYAFHQVGIHFS

Enzymatic activities:

Reaction	Substrate	Type	Position
A:m6A	rRNA (r)	SSU/18S/eukaryotic cytosol	1779
m6A:m6,6A	rRNA (r)	SSU/18S/eukaryotic cytosol	1779
A:m6A	rRNA (r)	SSU/18S/eukaryotic cytosol	1780
m6A:m6,6A	rRNA (r)	SSU/18S/eukaryotic cytosol	1780

Publications:

Title	Authors	Journal	Details	PubMed Id	DOI
Recognition of a complex substrate by the KsgA/Dim1 family of enzymes has been conserved throughout evolution.	O'Farrell HC, Pulicherla N, Desai PM, Rife JP	RNA	[details]	16540698	-
Structural and functional divergence within the Dim1/KsgA family of rRNA methyltransferases.	Pulicherla N, Pogorzala LA, Xu Z, O Farrell HC, Musayev FN, Scarsdale JN, Sia EA, Culver GM, Rife JP	J Mol Biol	[details]	19520088	-
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	[details]	8064863	-
Comprehensive phylogenetic analysis of evolutionarily conserved rRNA adenine dimethyltransferase suggests diverse bacterial contributions to the nucleus-encoded plastid proteome.	Park AK, Kim H, Jin HJ	Mol Phylogenet Evol	[details]	19017544	-
Dim2p, a KH-domain protein required for small ribosomal subunit synthesis.	Vanrobays E, Gelugne JP, Caizergues-Ferrer M, Lafontaine DL	RNA	[details]	15037774	-
Yeast 18S rRNA dimethylase Dim1p: a quality control mechanism in ribosome synthesis?	Lafontaine DL, Preiss T, Tollervey D	Mol Cell Biol	[details]	9528805	-