Class II Aminoacyl-tRNA Synthetases
The Class II aminoacyl-tRNA synthetases attach 13 of the 22 coded amino acids to their cognate tRNA. These amino acids are: the small polar (serine and threonine), the small (glycine, alanine, proline), the smaller acidic and amide groups (aspartate and asparagine), plus some of the aromatic (histidine and phenylalanine) and basic (lysine and pyrrolysine) residues.
Through post-translational modification of the aminoacyl-tRNA complex, they also enable the coding of cysteine and selenocysteine.
Class II synthetases are characterized by their catalytic domain, which has a six stranded antiparallel β sheet.
These catalytic domains fall into twenty one 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 IIa
Subclass IIb
Subclass IIc
Subclass IId
Subclass IIe
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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.
