SMART: tRNA_SAD domain annotation

tRNA_SAD Threonyl and Alanyl tRNA synthetase second additional domain

SMART accession number:	SM00863
Description:	The catalytically active form of threonyl/alanyl tRNA synthetase is a dimer. Within the tRNA synthetase class II dimer, the bound tRNA interacts with both monomers making specific interactions with the catalytic domain, the C-terminal domain, and this SAD domain (the second additional domain). The second additional domain is comprised of a pair of perpendicularly orientated antiparallel beta sheets, of four and three strands, respectively, that surround a central alpha helix that forms the core of the domain.
Family alignment:	View or

There are 2050 tRNA_SAD domains in 2050 proteins in SMART's nrdb database.

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Evolution (species in which this domain is found)
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This tree shows only several representative species. The complete taxonomic breakdown of all proteins with tRNA_SAD domain is also avaliable.

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Go to specific node: Anopheles gambiae, Arabidopsis thaliana, Caenorhabditis elegans, Drosophila melanogaster, Homo sapiens, Mus musculus, Rattus norvegicus, Saccharomyces cerevisiae, Takifugu rubripes
Cellular role (predicted cellular role)
Cellular role: translation
Literature (relevant references for this domain)
Primary literature is listed below; Automatically-derived, secondary literature is also avaliable.
- Sankaranarayanan R et al.
- The structure of threonyl-tRNA synthetase-tRNA(Thr) complex enlightens itsrepressor activity and reveals an essential zinc ion in the active site.
- Cell. 1999; 97: 371-81
- Display abstract
- E. coli threonyl-tRNA synthetase (ThrRS) is a class II enzyme thatrepresses the translation of its own mRNA. We report the crystal structureat 2.9 A resolution of the complex between tRNA(Thr) and ThrRS, whosestructural features reveal novel strategies for providing specificity intRNA selection. These include an amino-terminal domain containing a novelprotein fold that makes minor groove contacts with the tRNA acceptor stem.The enzyme induces a large deformation of the anticodon loop, resulting inan interaction between two adjacent anticodon bases, which accounts fortheir prominent role in tRNA identity and translational regulation. A zincion found in the active site is implicated in amino acidrecognition/discrimination.
Structure (3D structures containing this domain)

Links (links to other resources describing this domain)
PFAM tRNA_SAD

PDB code	Main view	Title
1nyq		Structure of staphylococcus aureus threonyl-trna synthetase complexed with an analogue of threonyl adenylate
1nyr		Structure of staphylococcus aureus threonyl-trna synthetase complexed with atp
1qf6		Structure of e. coli threonyl-trna synthetase complexed with its cognate trna
1tje		Crystal structure of the editing domain of threonyl-trna synthetase
1tke		Crystal structure of the editing domain of threonyl-trna synthetase complexed with serine
1tkg		Crystal structure of the editing domain of threonyl-trna synthetase complexed with an analog of seryladenylate
1tky		Crystal structure of the editing domain of threonyl-trna synthetase complexed with seryl-3'-aminoadenosine
2e1b		Crystal structure of the alax-m trans-editing enzyme from pyrococcus horikoshii
2ztg
2zze
2zzf
2zzg
3kew

tRNA_SAD

3D Structures of tRNA_SAD domains in PDB