Aminoacyl-tRNA synthetase (aaRS) is a key enzyme during protein biosynthesis. Each aaRS contains a catalytic central domain (CCD), responsible for activating amino acid, and an anticodon-binding domain (ABD), necessary for binding the anticodon in cognate tRNA. aaRSs are classified into class I and II (aaRS-I and aaRS-II) based on the topologies of CCDs. Whereas the structure of the CCDs is similar among the members of each of the two different aaRS classes, the ABDs are diverse in structure [].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. Both classes of tRNA synthetases have been subdivided into three subclasses, designated Ia, Ib, Ic and IIa, IIb, IIc.This superfamily represents the anticodon binding domain (ABD) of class Ia aminoacyl-tRNA synthetases, and also matches the ABD of glycine tRNA synthetases.
Aminoacyl-tRNA synthetases (aaRSs) play a crucial role in the translation of the genetic code by means of covalent attachment of amino acids to theircognate tRNAs. Phenylalanine-tRNA synthetase (PheRS, also known as Phenylalanine-tRNA ligase) is known to be among themost complex enzymes of the aaRS family. Bacterial and mitochondrial PheRSsshare a ferredoxin-fold anticodon binding (FDX-ACB) domain, which represents acanonical double split alpha+beta motif having no insertions. The FDX-ACBdomain displays a typical RNA recognition fold (RRM) (see ) formed by the four-stranded antiparallel beta sheet, with two helices packed against it [, , , , ].
Aminoacyl-tRNA synthetases (aaRSs) play a crucial role in the translation of the genetic code by means of covalent attachment of amino acids to theircognate tRNAs. Phenylalanine-tRNA synthetase (PheRS, also known as Phenylalanine-tRNA ligase) is known to be among themost complex enzymes of the aaRS family. Bacterial and mitochondrial PheRSsshare a ferredoxin-fold anticodon binding (FDX-ACB) domain, which represents acanonical double split alpha+beta motif having no insertions. The FDX-ACBdomain displays a typical RNA recognition fold (RRM) (see ) formed by the four-stranded antiparallel beta sheet, with two helices packed against it [, , , , ].
Aminoacyl-tRNA synthetase (aaRS) is a key enzyme during protein biosynthesis. Each aaRS contains a catalytic central domain (CCD), responsible for activating amino acid, and an anticodon-binding domain (ABD), necessary for binding the anticodon in cognate tRNA. aaRSs are classified into class I and II (aaRS-I and aaRS-II) based on the topologies of CCDs. Whereas the structure of the CCDs is similar among the members of each of the two different aaRS classes, the ABDs are diverse in structure [].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. Both classes of tRNA synthetases have been subdivided into three subclasses, designated Ia, Ib, Ic and IIa, IIb, IIc.This all alpha helical domain is the anticodon binding domain (ABD) of arginyl tRNA synthetase, and also matches the ABD of some glycine tRNA synthetases. This domain is known as the DALR domain after characteristic conserved amino acids [].
