Annotations: 3W3S

Domain Annotation: ECOD Classification ECOD Database Homepage

Chains	Family Name	Domain Identifier	Architecture	Possible Homology	Homology	Topology	Family	Provenance Source (Version)
A	PF18490	e3w3sA2	A: a+b two layers	X: LuxS, MPP, ThrRS/AlaRS common domain	H: LuxS, MPP, ThrRS/AlaRS common domain	T: ThrRS/AlaRS editing domain	F: PF18490	ECOD (1.6)
A	PF00587	e3w3sA1	A: a+b three layers	X: Class II aaRS and biotin synthetases (From Topology)	H: Class II aaRS and biotin synthetases (From Topology)	T: Class II aaRS and biotin synthetases	F: PF00587	ECOD (1.6)

Domain Annotation: CATH CATH Database Homepage

Chain	Domain	Class	Architecture	Topology	Homology	Provenance Source (Version)
A	3.30.70.1920	Alpha Beta	2-Layer Sandwich	Alpha-Beta Plaits		CATH (4.3.0)
A	3.30.930.10	Alpha Beta	2-Layer Sandwich	BirA Bifunctional Protein	domain 2	CATH (4.3.0)

Protein Family Annotation Pfam Database Homepage

Chains	Accession	Name	Description	Comments	Source
A	PF18490	tRNA-binding domain (tRNA_bind_4)	tRNA-binding domain	This is the N-terminal domain found in archeal type-2 serine-tRNA ligase (SerRS) (EC:6.1.1.11). The SerRS N-terminal domain interacts with the extra-arm stem and the outer corner of tRNA specific to Selenocysteine (tRNA-Sec) [1, 2].	Domain
A	PF00587	tRNA synthetase class II core domain (G, H, P, S and T) (tRNA-synt_2b)	tRNA synthetase class II core domain (G, H, P, S and T)	tRNA-synt_2b is a family of largely threonyl-tRNA members.	Domain

Gene Ontology: Gene Product Annotation Gene Ontology Database Homepage

Chains	Polymer	Molecular Function	Biological Process	Cellular Component
A	Type-2 serine--tRNA ligase	binding adenyl ribonucleotide binding nucleotide binding purine ribonucleotide binding purine ribonucleoside triphosphate binding nucleoside phosphate binding ion binding purine nucleotide binding organic cyclic compound binding anion binding adenyl nucleotide binding ATP binding heterocyclic compound binding carbohydrate derivative binding binding adenyl ribonucleotide binding nucleotide binding purine ribonucleotide binding purine ribonucleoside triphosphate binding nucleoside phosphate binding ion binding purine nucleotide binding organic cyclic compound binding anion binding adenyl nucleotide binding ATP binding heterocyclic compound binding carbohydrate derivative binding ribonucleotide binding small molecule binding ligase activity, forming carbon-oxygen bonds aminoacyl-tRNA ligase activity catalytic activity, acting on RNA serine-tRNA ligase activity catalytic activity, acting on a nucleic acid catalytic activity, acting on a tRNA catalytic activity ligase activity cation binding transition metal ion binding zinc ion binding metal ion binding	amino acid activation tRNA aminoacylation cellular biosynthetic process organonitrogen compound biosynthetic process RNA metabolic process amino acid metabolic process nucleobase-containing compound metabolic process organic substance metabolic process organic substance biosynthetic process protein metabolic process organonitrogen compound metabolic process cellular metabolic process primary metabolic process translation amino acid activation tRNA aminoacylation cellular biosynthetic process organonitrogen compound biosynthetic process RNA metabolic process amino acid metabolic process nucleobase-containing compound metabolic process organic substance metabolic process organic substance biosynthetic process protein metabolic process organonitrogen compound metabolic process cellular metabolic process primary metabolic process translation gene expression tRNA aminoacylation for protein translation macromolecule biosynthetic process nucleic acid metabolic process tRNA metabolic process organic cyclic compound metabolic process biosynthetic process ncRNA metabolic process seryl-tRNA aminoacylation metabolic process cellular process macromolecule metabolic process serine family amino acid metabolic process oxoacid metabolic process selenocysteine biosynthetic process organic acid metabolic process organic acid biosynthetic process alpha-amino acid metabolic process carboxylic acid biosynthetic process small molecule metabolic process small molecule biosynthetic process carboxylic acid metabolic process L-amino acid biosynthetic process L-amino acid metabolic process proteinogenic amino acid metabolic process selenocysteine metabolic process amino acid biosynthetic process proteinogenic amino acid biosynthetic process serine family amino acid biosynthetic process alpha-amino acid biosynthetic process	intracellular anatomical structure cytoplasm cellular anatomical entity
B	selenocysteine tRNA	-	-	-

InterPro: Protein Family Classification InterPro Database Homepage

Chains	Accession	Name	Type
A	IPR006195	Aminoacyl-tRNA synthetase, class II	Domain
A	IPR002314	Aminoacyl-tRNA synthetase, class II (G/ P/ S/T)	Domain
A	IPR045864	Class II Aminoacyl-tRNA synthetase/Biotinyl protein ligase (BPL) and lipoyl protein ligase (LPL)	Homologous Superfamily
A	IPR041293	Serine-tRNA ligase type 2, tRNA-binding domain	Domain
A	IPR004503	Serine-tRNA ligase type 2, archaea	Family

RCSB PDB Core Operations are funded by the U.S. National Science Foundation (DBI-2321666), the US Department of Energy (DE-SC0019749), and the National Cancer Institute, National Institute of Allergy and Infectious Diseases, and National Institute of General Medical Sciences of the National Institutes of Health under grant R01GM133198.