Class I Aminoacyl-tRNA Synthetases
The Class I aminoacyl-tRNA synthetases attach 11 of the 22 coded amino acids to their cognate tRNA. These amino acids are typically the larger and hydrophobic amino acids: the branched chain amino acids (leucine, valine, and isoleucine), the larger acidic and amide groups (glutamate and glutamine), plus some of the aromatic (tryptophan and tyrosine), and basic (lysine and arginine) residues as well as methionine and cysteine.
Class I synthetases are characterized by their catalytic domain, which adopts the Rossmann fold.
These catalytic domains fall into sixteen evolutionary families.
Each family shares common aminoacylation activity, has similar structure and sequence, and is monophyletic (or monophyletic with a second family contained within it).
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Families
Subclass Ia
Subclass Ib
Subclass Ic
Subclass Id
Subclass Ie
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Protein domains
tRNA binding domains
Editing domains
Other domains
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Structural pairwise comparison between families
The TM scores between catalytic domains are displayed below. Similar structures have larger scores within the range [0,1]. Click on a cell to visit the alignment.
