H
IPR008925

Aminoacyl-tRNA synthetase, class I, anticodon-binding superfamily

InterPro entry
Short nameaa_tRNA-synth_I_cd-bd_sf
Overlapping entries
 

Description

Structurally, an α-helix-bundle anticodon-binding domain characterises the class Ia synthetases, whereas the class Ib synthetases, GlnRS and GluRS have distinct anticodon-binding domains. The anticodon-binding domain has a multi-helical structure, consisting of two all-alpha subdomains. The Rossmann-fold, made up of alternate α-helices and β-sheets involved in ATP binding in the extended conformation, and the anticodon-binding domains are connected by a β-α-α-β-α topology ('SC fold') domain that contains the class I specific KMSKS motif
[6, 10]
.

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
[4, 3]
. These proteins differ widely in size and oligomeric state, and have limited sequence homology
[7]
. 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
[6]
. Class II aminoacyl-tRNA synthetases share an anti-parallel β-sheet fold flanked by α-helices
[2]
, and are mostly dimeric or multimeric, containing at least three conserved regions
[9, 8, 1]
. 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
[5]
.

References

1.Sequence, structural and evolutionary relationships between class 2 aminoacyl-tRNA synthetases. Cusack S, Hartlein M, Leberman R. Nucleic Acids Res. 19, 3489-98, (1991). View articlePMID: 1852601

2.Structural basis for transfer RNA aminoacylation by Escherichia coli glutaminyl-tRNA synthetase. Perona JJ, Rould MA, Steitz TA. Biochemistry 32, 8758-71, (1993). View articlePMID: 8364025

3.Aminoacyl-tRNA synthetases: versatile players in the changing theater of translation. Francklyn C, Perona JJ, Puetz J, Hou YM. RNA 8, 1363-72, (2002). View articlePMID: 12458790

4.Aminoacyl-tRNA synthetases, the genetic code, and the evolutionary process. Woese CR, Olsen GJ, Ibba M, Soll D. Microbiol. Mol. Biol. Rev. 64, 202-36, (2000). View articlePMID: 10704480

5.Evolution of aminoacyl-tRNA synthetases--analysis of unique domain architectures and phylogenetic trees reveals a complex history of horizontal gene transfer events. Wolf YI, Aravind L, Grishin NV, Koonin EV. Genome Res. 9, 689-710, (1999). View articlePMID: 10447505

6.The 2.0 A crystal structure of Thermus thermophilus methionyl-tRNA synthetase reveals two RNA-binding modules. Sugiura I, Nureki O, Ugaji-Yoshikawa Y, Kuwabara S, Shimada A, Tateno M, Lorber B, Giege R, Moras D, Yokoyama S, Konno M. Structure 8, 197-208, (2000). View articlePMID: 10673435

7.Partition of tRNA synthetases into two classes based on mutually exclusive sets of sequence motifs. Eriani G, Delarue M, Poch O, Gangloff J, Moras D. Nature 347, 203-6, (1990). View articlePMID: 2203971

8.Classes of aminoacyl-tRNA synthetases and the establishment of the genetic code. Schimmel P. Trends Biochem. Sci. 16, 1-3, (1991). View articlePMID: 2053131

9.The aminoacyl-tRNA synthetase family: modules at work. Delarue M, Moras D. Bioessays 15, 675-87, (1993). View articlePMID: 8274143

10.Aminoacyl-tRNA synthetases: Structure, function, and drug discovery. Rajendran V, Kalita P, Shukla H, Kumar A, Tripathi T. Int J Biol Macromol 111, 400-414, (2018). PMID: 29305884

GO terms

biological process

  • None

molecular function

cellular component

  • None

Cross References

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