Any feedback?
Please rate this page
(literature.php)
(0/150)

BRENDA support

Literature summary extracted from

  • O'Farrell, H.C.; Musayev, F.N.; Scarsdale, J.N.; Rife, J.P.
    Control of substrate specificity by a single active site residue of the KsgA methyltransferase (2012), Biochemistry, 51, 466-474.
    View publication on PubMed

Cloned(Commentary)

EC Number Cloned (Comment) Organism
2.1.1.182 expression of wild-type and mutant enzymes in Escherichia coli strain XL1-Blue Escherichia coli

Protein Variants

EC Number Protein Variants Comment Organism
2.1.1.182 C168A site-directed mutagenesis, the mutation does not affect KsgA activity Escherichia coli
2.1.1.182 L114P site-directed mutagenesis of the active site residue, the KsgA mutant shows diminished overall activity, and impaired ability to methylate the N6-methyladenosine intermediate to produce N6,N6-dimethyladenosine. Reduced activity is not due to disruption of 30S substrate binding Escherichia coli
2.1.1.182 N113A site-directed mutagenesis of the active site residue, the KsgA mutant shows diminishes activity to a level comparable to L114P without affecting the methylation of N6-methyladenosine. Reduced activity is not due to disruption of 30S substrate binding Escherichia coli

Natural Substrates/ Products (Substrates)

EC Number Natural Substrates Organism Comment (Nat. Sub.) Natural Products Comment (Nat. Pro.) Rev. Reac.
2.1.1.182 4 S-adenosyl-L-methionine + adenine1518/adenine1519 in 16S rRNA Escherichia coli
-
 4 S-adenosyl-L-homocysteine + N6-dimethyladenine1518/N6-dimethyladenine1519 in 16S rRNA
-
 ?

Organism

EC Number Organism UniProt Comment Textmining
2.1.1.182 Escherichia coli
-
-
-

Purification (Commentary)

EC Number Purification (Comment) Organism
2.1.1.182 recombinant wild-type and mutant enzymes from Escherichia coli strain XL1-Blue Escherichia coli

Reaction

EC Number Reaction Comment Organism Reaction ID
2.1.1.182 4 S-adenosyl-L-methionine + adenine1518/adenine1519 in 16S rRNA = 4 S-adenosyl-L-homocysteine + N6-dimethyladenine1518/N6-dimethyladenine1519 in 16S rRNA reaction mechanism, overview Escherichia coli
a

Substrates and Products (Substrate)

EC Number Substrates Comment Substrates Organism Products Comment (Products) Rev. Reac.
2.1.1.182 4 S-adenosyl-L-methionine + adenine1518/adenine1519 in 16S rRNA
-
 Escherichia coli 4 S-adenosyl-L-homocysteine + N6-dimethyladenine1518/N6-dimethyladenine1519 in 16S rRNA
-
 ?
2.1.1.182 4 S-adenosyl-L-methionine + adenine1518/adenine1519 in 16S rRNA binding of 30S subunit and S-adenosyl-L-methionine, structure, overview. After the S-adenosyl-L-methionine addition, KsgA dissociates rapidly from the subunits. The binding of KsgA to substrate is complex and requires regions of rRNA well beyond helix 45, including regions of the 790 loop Escherichia coli 4 S-adenosyl-L-homocysteine + N6-dimethyladenine1518/N6-dimethyladenine1519 in 16S rRNA
-
 ?

Synonyms

EC Number Synonyms Comment Organism
2.1.1.182 ksgA methyltransferase
-
 Escherichia coli

Temperature Optimum [°C]

EC Number Temperature Optimum [°C] Temperature Optimum Maximum [°C] Comment Organism
2.1.1.182 30
-
 assay at Escherichia coli

pH Optimum

EC Number pH Optimum Minimum pH Optimum Maximum Comment Organism
2.1.1.182 7.4
-
 assay at Escherichia coli

Cofactor

EC Number Cofactor Comment Organism Structure
2.1.1.182 S-adenosyl-L-methionine
-
 Escherichia coli

IC50 Value

EC Number IC50 Value IC50 Value Maximum Comment Organism Inhibitor Structure
2.1.1.182 additional information
-
 IC50 values of unlabeled wild-type or mutant protein competing with fluorescently labeled wild-type protein for binding to 30S subunits Escherichia coli additional information

General Information

EC Number General Information Comment Organism
2.1.1.182 evolution the KsgA family belongs tothe group of S-adenosyl-L-methionine-dependent methyltransferases, known as class I MTases, KsgA is related to DNA adenosine methyltransferases, which transfer only a single methyl group to their target adenosine residue. Part of the discrimination between mono- and dimethyltransferase activity lies in a single residue in the active site, L114; this residue is part of a conserved motif, known as motif IV, which is common to a large group of S-adenosyl-L-methionine-dependent methyltransferases Escherichia coli
2.1.1.182 physiological function the KsgA methyltransferase is universally conserved and plays a key role in regulating ribosome biogenesis. KsgA has a complex reaction mechanism, transferring a total of four methyl groups onto two separate adenosine residues, A1518 and A1519, in the small subunit rRNA. This means that the active site pocket must accept both adenosine and N6-methyladenosine as substrates to catalyze formation of the final product N6,N6-dimethyladenosine Escherichia coli