ID:SEN2_HUMAN DESCRIPTION: RecName: Full=tRNA-splicing endonuclease subunit Sen2; EC=3.1.27.9; AltName: Full=tRNA-intron endonuclease Sen2; Short=HsSen2; FUNCTION: Constitutes one of the two catalytic subunit of the tRNA-splicing endonuclease complex, a complex responsible for identification and cleavage of the splice sites in pre-tRNA. It cleaves pre-tRNA at the 5'- and 3'-splice sites to release the intron. The products are an intron and two tRNA half-molecules bearing 2',3'-cyclic phosphate and 5'-OH termini. There are no conserved sequences at the splice sites, but the intron is invariably located at the same site in the gene, placing the splice sites an invariant distance from the constant structural features of the tRNA body. Isoform 1 probably carries the active site for 5'-splice site cleavage. The tRNA splicing endonuclease is also involved in mRNA processing via its association with pre- mRNA 3'-end processing factors, establishing a link between pre- tRNA splicing and pre-mRNA 3'-end formation, suggesting that the endonuclease subunits function in multiple RNA-processing events. Isoform 2 is responsible for processing a yet unknown RNA substrate. The complex containing isoform 2 is not able to cleave pre-tRNAs properly, although it retains endonucleolytic activity. CATALYTIC ACTIVITY: Endonucleolytic cleavage of pre-tRNA, producing 5'-hydroxy and 2',3'-cyclic phosphate termini, and specifically removing the intron. SUBUNIT: tRNA splicing endonuclease is a heterotetramer composed of isoform 1 of SEN2, SEN15, SEN34/LENG5 and SEN54. tRNA splicing endonuclease complex also contains proteins of the pre-mRNA 3'-end processing machinery such as CLP1, CPSF1, CPSF4 and CSTF2. Isoform 2 belongs to a different complex that contains SEN54 but low level of SEN15 and SEN34/LENG5. SUBCELLULAR LOCATION: Nucleus. Nucleus, nucleolus. Note=May be transiently localized in the nucleolus. TISSUE SPECIFICITY: Isoform 1 and isoform 2 are widely expressed at very low level. PTM: Phosphorylated upon DNA damage, probably by ATM or ATR. DISEASE: Defects in TSEN2 are the cause of pontocerebellar hypoplasia type 2B (PCH2B) [MIM:612389]. Pontocerebellar hypoplasia (PCH) is a heterogeneous group of disorders characterized by an abnormally small cerebellum and brainstem. PCH type 2 is characterized by progressive microcephaly from birth combined with extrapyramidal dyskinesia and chorea, epilepsy, and normal spinal cord findings. SIMILARITY: Belongs to the tRNA-intron endonuclease family.
The RNAfold program from the Vienna RNA Package is used to perform the secondary structure predictions and folding calculations. The estimated folding energy is in kcal/mol. The more negative the energy, the more secondary structure the RNA is likely to have.
ModBase Predicted Comparative 3D Structure on Q8NCE0
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Orthologous Genes in Other Species
Orthologies between human, mouse, and rat are computed by taking the best BLASTP hit, and filtering out non-syntenic hits. For more distant species reciprocal-best BLASTP hits are used. Note that the absence of an ortholog in the table below may reflect incomplete annotations in the other species rather than a true absence of the orthologous gene.
US Server
Sequence and Links to Tools and Databases 
Common Gene Haplotype Alleles 
