Summary: tRNA synthetases class I (E and Q), catalytic domain
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Aminoacyl tRNA synthetases, class I Edit Wikipedia article
|Glutamyl/glutaminyl-tRNA synthetase, class Ic|
The aminoacyl-tRNA synthetases 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 Rossmann 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; these synthetases are further divided into three subclasses, a, b and c, according to sequence homology. The synthetases specific for alanine, asparagine, aspartic acid, glycine, histidine, lysine, phenylalanine, proline, serine, and threonine belong to class-II synthetases.
Glutamyl-tRNA synthetase (EC 22.214.171.124) is a class Ic synthetase and shows several similarities with glutaminyl-tRNA synthetase concerning structure and catalytic properties. It is an alpha2 dimer. To date one crystal structure of a glutamyl-tRNA synthetase (Thermus thermophilus) has been solved. The molecule has the form of a bent cylinder and consists of four domains. The N-terminal half (domains 1 and 2) contains the 'Rossman fold' typical for class I synthetases and resembles the corresponding part of E. coli GlnRS, whereas the C-terminal half exhibits a GluRS-specific structure.
Human proteins containing this domain
- Delarue M, Moras D, Poch O, Eriani G, Gangloff J (1990). "Partition of tRNA synthetases into two classes based on mutually exclusive sets of sequence motifs". Nature. 347 (6289): 203â€“206. doi:10.1038/347203a0. PMIDÂ 2203971. S2CIDÂ 4324290.
- Moras D, Konno M, Shimada A, Nureki O, Tateno M, Yokoyama S, Sugiura I, Ugaji-Yoshikawa Y, Kuwabara S, Lorber B, Giege R (2000). "The 2.0 A crystal structure of Thermus thermophilus methionyl-tRNA synthetase reveals two RNA-binding modules". Structure. 8 (2): 197â€“208. doi:10.1016/S0969-2126(00)00095-2. PMIDÂ 10673435.
- Perona JJ, Steitz TA, Rould MA (1993). "Structural basis for transfer RNA aminoacylation by Escherichia coli glutaminyl-tRNA synthetase". Biochemistry. 32 (34): 8758â€“8771. doi:10.1021/bi00085a006. PMIDÂ 8364025.
- Delarue M, Moras D (1993). "The aminoacyl-tRNA synthetase family: modules at work". BioEssays. 15 (10): 675â€“687. doi:10.1002/bies.950151007. PMIDÂ 8274143. S2CIDÂ 35612984.
- Schimmel P (1991). "Classes of aminoacyl-tRNA synthetases and the establishment of the genetic code". Trends Biochem. Sci. 16 (1): 1â€“3. doi:10.1016/0968-0004(91)90002-D. PMIDÂ 2053131.
- Cusack S, Leberman R, Hartlein M (1991). "Sequence, structural and evolutionary relationships between class 2 aminoacyl-tRNA synthetases". Nucleic Acids Res. 19 (13): 3489â€“3498. doi:10.1093/nar/19.13.3489. PMCÂ 328370. PMIDÂ 1852601.
- Bairoch A (2004). "List of aminoacyl-tRNA synthetases". Cite journal requires
- Soll D, Freist W, Gauss DH, Lapointe J (1997). "Glutamyl-tRNA sythetase". Biol. Chem. 378 (11): 1313â€“1329. doi:10.1515/bchm.1997.378.11.1299. PMIDÂ 9426192.
This tab holds the annotation information that is stored in the Pfam database. As we move to using Wikipedia as our main source of annotation, the contents of this tab will be gradually replaced by the Wikipedia tab.
tRNA synthetases class I (E and Q), catalytic domain Provide feedback
Other tRNA synthetase sub-families are too dissimilar to be included. This family includes only glutamyl and glutaminyl tRNA synthetases. In some organisms, a single glutamyl-tRNA synthetase aminoacylates both tRNA(Glu) and tRNA(Gln).
Internal database links
|Similarity to PfamA using HHSearch:||tRNA-synt_1e tRNA-synt_1f tRNA-synt_1g|
External database links
This tab holds annotation information from the InterPro database.
InterPro entry IPR020058
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 [ PUBMED:10704480 , PUBMED:12458790 ]. These proteins differ widely in size and oligomeric state, and have limited sequence homology [ PUBMED:2203971 ]. 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 [ PUBMED:10673435 ]. Class II aminoacyl-tRNA synthetases share an anti-parallel beta-sheet fold flanked by alpha-helices [ PUBMED:8364025 ], and are mostly dimeric or multimeric, containing at least three conserved regions [ PUBMED:8274143 , PUBMED:2053131 , PUBMED:1852601 ]. 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, 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 [ PUBMED:10447505 ].
Glutamate-tRNA ligase (also known as glutamyl-tRNA synthetase; EC ) is a class Ic ligase and shows several similarities with glutamate-tRNA ligase concerning structure and catalytic properties. It is an alpha2 dimer. To date one crystal structure of a glutamate-tRNA ligase (Thermus thermophilus) has been solved. The molecule has the form of a bent cylinder and consists of four domains. The N-terminal half (domains 1 and 2) contains the 'Rossman fold' typical for class I ligases and resembles the corresponding part of Escherichia coli GlnRS, whereas the C-terminal half exhibits a GluRS-specific structure [ PUBMED:9426192 ].
The mapping between Pfam and Gene Ontology is provided by InterPro. If you use this data please cite InterPro.
|Molecular function||ATP binding (GO:0005524)|
|aminoacyl-tRNA ligase activity (GO:0004812)|
|Biological process||tRNA aminoacylation (GO:0043039)|
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The HUP class contains the HIGH-signature proteins, UspA superfamily and the PP-ATPase superfamily . The HIGH superfamily has the HIGH Nucleotidyl transferases and the class I tRNA synthetases both of which have the HIGH and the KMSKS motif ,. The PP-loop ATPase named after the ATP PyroPhosphatase domain, was initially identified as a conserved amino acid sequence motif in four distinct groups of enzymes that catalyse the hydrolysis of the alpha-beta phosphate bond of ATP, namely GMP synthetases, argininosuccinate synthetases, asparagine synthetases, and ATP sulfurylases . The USPA superfamily contains USPA, ETFP and Photolyases 
The clan contains the following 32 members:Arginosuc_synth Asn_synthase ATP-sulfurylase ATP_bind_3 BshC CDPS Citrate_ly_lig CTP_transf_like Diphthami_syn_2 DNA_photolyase DPRP ETF FAD_syn HIGH_NTase1 HIGH_NTase1_ass NAD_synthase Pantoate_ligase PAPS_reduct QueC QueH ThiI tRNA-synt_1 tRNA-synt_1_2 tRNA-synt_1b tRNA-synt_1c tRNA-synt_1d tRNA-synt_1e tRNA-synt_1f tRNA-synt_1g tRNA_Me_trans UDPG_MGDP_dh_C Usp
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1Cannot generate PP/Heatmap alignments for seeds; no PP data available
Key: available, not generated, — not available.
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|Seed source:||Pfam-B_350 (release 2.1)|
|Author:||Bateman A , Griffiths-Jones SR|
|Number in seed:||16|
|Number in full:||24704|
|Average length of the domain:||284.70 aa|
|Average identity of full alignment:||29 %|
|Average coverage of the sequence by the domain:||55.26 %|
|HMM build commands:||
build method: hmmbuild -o /dev/null HMM SEED
search method: hmmsearch -Z 61295632 -E 1000 --cpu 4 HMM pfamseq
|Family (HMM) version:||24|
|Download:||download the raw HMM for this family|
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For all of the domain matches in a full alignment, we count the number that are found on all sequences in the alignment. This total is shown in the purple box.
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For those sequences which have a structure in the Protein DataBank, we use the mapping between UniProt, PDB and Pfam coordinate systems from the PDBe group, to allow us to map Pfam domains onto UniProt sequences and three-dimensional protein structures. The table below shows the structures on which the tRNA-synt_1c domain has been found. There are 82 instances of this domain found in the PDB. Note that there may be multiple copies of the domain in a single PDB structure, since many structures contain multiple copies of the same protein sequence.
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AlphaFold Structure Predictions
The list of proteins below match this family and have AlphaFold predicted structures. Click on the protein accession to view the predicted structure.