| Type: | Family | Name: | Aspartyl/Asparaginyl-tRNA synthetase, class IIb |
| Description: | Aspartyl tRNA synthetase is an alpha2 dimer that belongs to class IIb. Structural analysis combined with mutagenesis and enzymology data on the yeast enzyme point to a tRNA binding process that starts by a recognition event between the tRNA anticodon loop and the synthetase anticodon binding module []. The aminoacyl-tRNA synthetase (also known as aminoacyl-tRNA ligase) catalyse the attachment of an amino acid to its cognate transfer RNA molecule in a highly specific two-step reaction. These proteins differ widely in size and oligomeric state, and have limited sequence homology []. The 20 aminoacyl-tRNA synthetases are divided into two classes, I and II. Class I aminoacyl-tRNA synthetases contain a characteristic Rossman fold catalytic domain and are mostly monomeric []. Class II aminoacyl-tRNA synthetases share an anti-parallel beta-sheet fold flanked by alpha-helices [], and are mostly dimeric or multimeric, containing at least three conserved regions [, , ]. However, tRNA binding involves an alpha-helical structure that is conserved between class I and class II synthetases. In reactions catalysed by the class I aminoacyl-tRNA synthetases, the aminoacyl group is coupled to the 2'-hydroxyl of the tRNA, while, in class II reactions, the 3'-hydroxyl site is preferred. The synthetases specific for arginine, cysteine, glutamic acid, glutamine, isoleucine, leucine, methionine, tyrosine, tryptophan and valine belong to class I synthetases. The synthetases specific for alanine, asparagine, aspartic acid, glycine, histidine, lysine, phenylalanine, proline, serine, and threonine belong to class-II synthetases. Based on their mode of binding to the tRNA acceptor stem, both classes of tRNA synthetases have been subdivided into three subclasses, designated 1a, 1b, 1c and 2a, 2b, 2c. | Short Name: | Asp/Asn-tRNA-synth_IIb |
| GO Term | Gene Name |
|---|---|
| GO:0000166 | IPR002312 |
| GO:0004812 | IPR002312 |
| GO:0005524 | IPR002312 |
| GO:0006418 | IPR002312 |
| GO Term | Gene Name |
|---|---|
| GO:0000166 | IPR002312 |
| GO:0004812 | IPR002312 |
| GO:0005524 | IPR002312 |
| GO:0006418 | IPR002312 |
| DB identifier | Type | Name |
|---|---|---|
| IPR018150 | Family | Aminoacyl-tRNA synthetase, class II (D/K/N)-like |
