EEFSEC

EEFSEC
Identifiers
Aliases	EEFSEC, EFSEC, SELB, eukaryotic elongation factor, selenocysteine-tRNA-specific, eukaryotic elongation factor, selenocysteine-tRNA specific
External IDs	OMIM: 607695; MGI: 2137092; GeneCards: EEFSEC
Gene location (Human)
Chr.	Chromosome 3 (human)
End	128,408,646 bp
Gene location (Mouse)
Chr.	Chromosome 6 (mouse)
End	88,423,521 bp
RNA expression pattern
	Top expressed in
	apex of heart; ; left ventricle; ; gastrocnemius muscle; ; muscle of thigh; ; granulocyte; ; right lobe of liver; ; left uterine tube; ; skeletal muscle tissue; ; right auricle of heart; ; popliteal artery;
	Top expressed in
	spermatocyte; ; spermatid; ; yolk sac; ; seminiferous tubule; ; left lobe of liver; ; secondary oocyte; ; thymus; ; proximal tubule; ; right kidney; ; zygote;
	More reference expression data
	n/a
Gene ontology
Molecular function	tRNA binding; nucleotide binding; ribonucleoprotein complex binding; GTP binding; selenocysteine insertion sequence binding; translation elongation factor activity; GTPase activity;
Cellular component	cytoplasm; nucleus; ribonucleoprotein complex;
Biological process	selenocysteine incorporation; protein biosynthesis; translational elongation;
	Sources:Amigo / QuickGO
Orthologs
Databases	NCBI: entry; OMA: entry
	60678
	65967
	ENSG00000132394
	ENSMUSG00000033216
	P57772
	Q9JHW4
	NM_021937
	NM_023060
	NP_068756
	NP_075547
	Wikidata
View/Edit Human	View/Edit Mouse

Selenocysteine-specific elongation factor (eEFSec) is an enzyme that in humans is encoded by the gene EEFSEC (eukaryotic elongation factor, selenocysteine-tRNA specific). This enzyme is involved in incorporating the non-standard amino acid selenocysteine into selenoproteins. In particular, it binds to SECISBP2, and acts as an elongation factor that replaces the eRF1-eRF3-GTP complex for insertion of selenocysteine in response to the opal stop codon UGA. This protein has sometimes been called SELB or eSelB (eukaryotic SelB) in reference to the analogous bacterial enzyme, SelB.

Medical Significance

Pathogenic mutations in EEFSEC are associated with an autosomal recessive disorder called neurodevelopmental disorder with progressive spasticity and brain abnormalities (NEDPSB). Those affected have impaired intellectual development and often struggle with speech. There is also typically muscle dysfunction (hypotonia, delayed walking), which often progresses to spasticity, and some of those affected become wheel-chair bound.

References

1 2 3 GRCh38: Ensembl release 89: ENSG00000132394 – Ensembl, May 2017
1 2 3 GRCm38: Ensembl release 89: ENSMUSG00000033216 – Ensembl, May 2017
↑ "Human PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
↑ "Mouse PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
1 2 3 "Selenocysteine-specific elongation factor". uniprot.org. UniProt consortium. Retrieved 2026-10-24.
1 2 Peng JJ, Yue SY, Fang YH, Liu XL, Wang CH (2021-11-25). "Mechanisms affecting the biosynthesis and incorporation rate of selenocysteine". Molecules. 26 (23): 7120. doi:10.3390/molecules26237120.
1 2 3 Kniffin CL (2025-02-25). "NEURODEVELOPMENTAL DISORDER WITH PROGRESSIVE SPASTICITY AND BRAIN ABNORMALITIES; NEDPSB". OMIM. Johns Hopkins university. Retrieved 2026-10-24.

This article on a gene on human chromosome 3 is a stub. You can help Wikipedia by adding missing information.

[refGRCh38Ensembl-1] 1 2 3 GRCh38: Ensembl release 89: ENSG00000132394 – Ensembl, May 2017

[refGRCm38Ensembl-2] 1 2 3 GRCm38: Ensembl release 89: ENSMUSG00000033216 – Ensembl, May 2017

[3] "Human PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.

[4] "Mouse PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.

[uniprot-5] 1 2 3 "Selenocysteine-specific elongation factor". uniprot.org. UniProt consortium. Retrieved 2026-10-24.

[Peng2021-6] 1 2 Peng JJ, Yue SY, Fang YH, Liu XL, Wang CH (2021-11-25). "Mechanisms affecting the biosynthesis and incorporation rate of selenocysteine". Molecules. 26 (23): 7120. doi:10.3390/molecules26237120.

[omim-7] 1 2 3 Kniffin CL (2025-02-25). "NEURODEVELOPMENTAL DISORDER WITH PROGRESSIVE SPASTICITY AND BRAIN ABNORMALITIES; NEDPSB". OMIM. Johns Hopkins university. Retrieved 2026-10-24.