Summary: tRNA synthetase class II core domain (G, H, P, S and T)
The Pfam group coordinates the annotation of Pfam families in Wikipedia, but we have not yet assigned a Wikipedia article to this family. If you think that a particular Wikipedia article provides good annotation, please let us know.
tRNA synthetase class II core domain (G, H, P, S and T) Provide feedback
tRNA-synt_2b is a family of largely threonyl-tRNA members.
Wolf YI, Aravind L, Grishin NV, Koonin EV; , Genome Res 1999;9:689-710.: Evolution of aminoacyl-tRNA synthetases--analysis of unique domain architectures and phylogenetic trees reveals a complex history of horizontal gene transfer events. PUBMED:10447505 EPMC:10447505
Internal database links
|SCOOP:||tRNA-synt_2d GAD tRNA_edit tRNA-synt_His|
|Similarity to PfamA using HHSearch:||tRNA-synt_2d tRNA-synt_His|
External database links
This tab holds annotation information from the InterPro database.
InterPro entry IPR002314
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 [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 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.
This domain is the core catalytic domain of tRNA synthetases and includes glycyl, histidyl, prolyl, seryl and threonyl tRNA synthetases.
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)|
|nucleotide binding (GO:0000166)|
|aminoacyl-tRNA ligase activity (GO:0004812)|
|Biological process||tRNA aminoacylation for protein translation (GO:0006418)|
- the number of sequences which exhibit this architecture
a textual description of the architecture, e.g. Gla, EGF x 2, Trypsin.
This example describes an architecture with one
Gladomain, followed by two consecutive
EGFdomains, and finally a single
- the UniProt description of the protein sequence
- the number of residues in the sequence
- the Pfam graphic itself.
Loading domain graphics...
Aminoacyl-tRNA synthetases are key components of the protein translation machinery that catalyse two basic reactions. First, the activation of amino acids via the formation of aminoacyl adenylates and second, linking the activated amino acid to the cognate tRNAs. The aminoacyl-tRNA synthetases generate AMP as the second end product of this reaction, which differentiates them from the majority of ATP-dependent enzymes that produce ADP. In addition, there is a specific aminoacyl-tRNA synthetases for each of the 20 amino acids and there are two structurally distinct classes of aminoacyl-tRNA synthetases, each encompassing 10 different specificities. The two classes have alternative modes of aminoacylation: class I aminoacylate the 2'OH of the cognate tRNA; class II aminoacylate 3'OH (with the exception of PheRS). Each class contain a conserved core domain that is involved in ATP binding and hydrolysis and combines with additional domains that determine the specificity of interactions with the cognate amino acid and tRNA. The class II core domain consist of a mixed-beta sheet, similar to that found in the biotin synthetases, hence why this family has also been included in this clan. The core domain contains three modestly conserved motifs that are responsible for ATP binding. The class II aminoacyl-tRNA synthetases can contain additional nested domains, found inserted in the loops of the core domain  (and reference therein).
The clan contains the following 10 members:AsnA BPL_LplA_LipB BPL_LplA_LipB_2 DUF366 tRNA-synt_2 tRNA-synt_2b tRNA-synt_2c tRNA-synt_2d tRNA-synt_2e tRNA-synt_His
We make a range of alignments for each Pfam-A family:
- the curated alignment from which the HMM for the family is built
- the alignment generated by searching the sequence database using the HMM
- Representative Proteomes (RPs) at 15%, 35%, 55% and 75% co-membership thresholds
- alignment generated by searching the UniProtKB sequence database using the family HMM
- alignment generated by searching the NCBI sequence database using the family HMM
- alignment generated by searching the metagenomics sequence database using the family HMM
You can see the alignments as HTML or in three different sequence viewers:
1Cannot generate PP/Heatmap alignments for seeds; no PP data available
Key: available, not generated, — not available.
Format an alignment
If you find these logos useful in your own work, please consider citing the following article:
Note: You can also download the data file for the tree.
Curation and family details
|Seed source:||pdb_id 3ial,2dq3,3ugt,1evk,3vbb,1kmn,2j3l,3a31|
|Number in seed:||8|
|Number in full:||9320|
|Average length of the domain:||220.00 aa|
|Average identity of full alignment:||21 %|
|Average coverage of the sequence by the domain:||39.64 %|
|HMM build commands:||
build method: hmmbuild -o /dev/null --hand HMM SEED
search method: hmmsearch -Z 11927849 -E 1000 --cpu 4 HMM pfamseq
|Family (HMM) version:||22|
|Download:||download the raw HMM for this family|
Weight segments by...
Change the size of the sunburst
selected sequences to HMM
a FASTA-format file
- 0 sequences
- 0 species
How the sunburst is generated
Colouring and labels
Anomalies in the taxonomy tree
Missing taxonomic levels
Unmapped species names
Too many species/sequences
The tree shows the occurrence of this domain across different species. More...
You can use the tree controls to manipulate how the interactive tree is displayed:
- show/hide the summary boxes
- highlight species that are represented in the seed alignment
- expand/collapse the tree or expand it to a given depth
- select a sub-tree or a set of species within the tree and view them graphically or as an alignment
- save a plain text representation of the tree
There are 11 interactions for this family. More...
We determine these interactions using iPfam, which considers the interactions between residues in three-dimensional protein structures and maps those interactions back to Pfam families. You can find more information about the iPfam algorithm in the journal article that accompanies the website.
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_2b domain has been found. There are 194 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 seqence.
Loading structure mapping...