EC Number   |
Substrates |
Organism |
Products |
Reversibility |
|---|
  2.1.1.172 | S-adenosyl-L-methionine + guanine1207 in 16S rRNA |
- |
Escherichia coli |
S-adenosyl-L-homocysteine + N2-methylguanine1207 in 16S rRNA |
- |
? |
| 2.1.1.172 | S-adenosyl-L-methionine + guanine1207 in 16S rRNA |
because the m2G1207 methyltransferase reacts with 30S particles but barely at all with 16S RNA, it seems likely that methylation of the guanine residue occurs after the 16S RNA has associated with some ribosomal proteins |
Escherichia coli |
S-adenosyl-L-homocysteine + N2-methylguanine1207 in 16S rRNA |
- |
? |
| 2.1.1.172 | S-adenosyl-L-methionine + guanine1207 in 16S rRNA |
RsmD methyltransferase utilizes assembled ribosomal small subunit or its late assembly intermediates as a substrate. It is likely it uses the decoding cleft of the small subunit as the binding site. Nucleotide N2-methylguanine1207 is located in the helix 34 of the 16S rRNA. This functionally important helix is involved in the formation of the binding pocket for A-site bound tRNA and translocation. Despite location in the very functionally important region of the 30S subunit, N2-methylguanine1207 is not involved in the contact with tRNA. Methylation of G1207 may be necessary to freeze secondary structure in the functional conformation |
Escherichia coli |
S-adenosyl-L-homocysteine + N2-methylguanine1207 in 16S rRNA |
- |
? |
| 2.1.1.172 | S-adenosyl-L-methionine + guanine1207 in 16S rRNA |
the enzyme reacts well with 30S subunits reconstituted from 16S RNA transcripts and 30S proteins but is almost inactive with the corresponding free RNA. Of the three naturally occurring N2-methylguanine residues, only N2-methylguanine1207 is formed. It is suggested that the optimal substrate may be a ribonucleoprotein particle less structured than a 30S ribosome but more so than free RNA. Localization of the site of methylation by hybridization-protection studies using deoxyoligomers that are complementary to the RNA sequence spanning each of the N2-methylguanine sites |
Escherichia coli |
S-adenosyl-L-homocysteine + N2-methylguanine1207 in 16S rRNA |
- |
? |
