| Type: | Family | Name: | Alanine-tRNA ligase, class IIc |
| Description: | Alanine-tRNA ligase (also known as alanyl-tRNA synthetase) () is an alpha4 tetramer that belongs to class IIc. 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: | Ala-tRNA-lgiase_IIc |
| DB identifier | Type | Name |
|---|---|---|
| IPR003156 | Domain | DHHA1 domain |
| IPR018162 | Domain | Alanine-tRNA ligase, class IIc, anti-codon-binding domain |
| IPR012947 | Domain | Threonyl/alanyl tRNA synthetase, SAD |
| IPR018163 | Domain | Threonyl/alanyl tRNA synthetase, class II-like, putative editing domain |
| IPR018165 | Domain | Alanyl-tRNA synthetase, class IIc, core domain |
| IPR018164 | Domain | Alanyl-tRNA synthetase, class IIc, N-terminal |
