LIS - Legume Information System
Information about legume traits for crop improvement
CicerMine
v5.1.0.3
Cicer data from the Legume Information System
v5.1.0.3
Cicer data from the Legume Information System
| Type | Homologous_superfamily |
| Description | The aminoacyl-tRNA synthetases (also known as aminoacyl-tRNA ligases) 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 β-sheet fold flanked by α-helices [], and are mostly dimeric or multimeric, containing at least three conserved regions [, , ]. However, tRNA binding involves an α-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, valine, and some lysine synthetases (non-eukaryotic group) belong to class I synthetases. The synthetases specific for alanine, asparagine, aspartic acid, glycine, histidine, phenylalanine, proline, serine, threonine, and some lysine synthetases (non-archaeal group), 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 [].The N-terminal appended domain (NTD) of glutaminyl-tRNA synthetase consists consists of two alpha helical domains, the first from containing a seven-helix bundle, and the second containing a four-helix bundle, which are connected by a seven residue linker [ ]. It is thought to bind RNA in a non-specific manner, enhancing interactions between the tRNA and enzyme, but is not essential for enzyme function [].This superfamily represents the subdomain 1 found at the N-terminal of glutaminyl-tRNA synthetase ( ) in eukaryotes but not in Escherichia coli. |
| Short Name | Gln-tRNA-synth_Ib_RNA-bd_N_1 |
