Q5TM17 · DX39B_MACMU
- ProteinSpliceosome RNA helicase DDX39B
- GeneDDX39B
- StatusUniProtKB reviewed (Swiss-Prot)
- Organism
- Amino acids428 (go to sequence)
- Protein existenceInferred from homology
- Annotation score4/5
Function
function
Involved in nuclear export of spliced and unspliced mRNA. Component of the TREX complex which is thought to couple mRNA transcription, processing and nuclear export, and specifically associates with spliced mRNA and not with unspliced pre-mRNA. The TREX complex is recruited to spliced mRNAs by a transcription-independent mechanism, binds to mRNA upstream of the exon-junction complex (EJC) and is recruited in a splicing- and cap-dependent manner to a region near the 5' end of the mRNA where it functions in mRNA export to the cytoplasm via the TAP/NXF1 pathway. The THOC1-THOC2-THOC3 core complex alone is sufficient to promote ATPase activity of DDX39B; in the complex THOC2 is the only component that directly interacts with DDX39B. Associates with SARNP/CIP29, which facilitates RNA binding of DDX39B and likely plays a role in mRNA export. May undergo several rounds of ATP hydrolysis during assembly of TREX to drive subsequent loading of components such as ALYREF/THOC4 and CHTOP onto mRNA. Also associates with pre-mRNA independent of ALYREF/THOC4. Involved in the nuclear export of intronless mRNA; the ATP-bound form is proposed to recruit export adapter ALYREF/THOC4 to intronless mRNA; its ATPase activity is cooperatively stimulated by RNA and ALYREF/THOC4 and ATP hydrolysis is thought to trigger the dissociation from RNA to allow the association of ALYREF/THOC4 and the NXF1-NXT1 heterodimer. Involved in transcription elongation and genome stability.
Splice factor that is required for the first ATP-dependent step in spliceosome assembly and for the interaction of U2 snRNP with the branchpoint. Has both RNA-stimulated ATP binding/hydrolysis activity and ATP-dependent RNA unwinding activity. Even with the stimulation of RNA, the ATPase activity is weak. Can only hydrolyze ATP but not other NTPs. The RNA stimulation of ATPase activity does not have a strong preference for the sequence and length of the RNA. However, ssRNA stimulates the ATPase activity much more strongly than dsRNA. Can unwind 5' or 3' overhangs or blunt end RNA duplexes in vitro. The ATPase and helicase activities are not influenced by U2AF2; the effect of ALYREF/THOC4 is reported conflictingly.
Catalytic activity
- ATP + H2O = ADP + H+ + phosphate
Features
Showing features for binding site.
GO annotations
Aspect | Term | |
---|---|---|
Cellular Component | cytoplasm | |
Cellular Component | nuclear speck | |
Cellular Component | spliceosomal complex | |
Molecular Function | ATP binding | |
Molecular Function | ATP hydrolysis activity | |
Molecular Function | mRNA binding | |
Molecular Function | RNA helicase activity | |
Biological Process | mRNA export from nucleus | |
Biological Process | mRNA splicing, via spliceosome |
Keywords
- Molecular function
- Biological process
- Ligand
Enzyme and pathway databases
Names & Taxonomy
Protein names
- Recommended nameSpliceosome RNA helicase DDX39B
- EC number
- Alternative names
Gene names
Organism names
- Organism
- Taxonomic lineageEukaryota > Metazoa > Chordata > Craniata > Vertebrata > Euteleostomi > Mammalia > Eutheria > Euarchontoglires > Primates > Haplorrhini > Catarrhini > Cercopithecidae > Cercopithecinae > Macaca
Accessions
- Primary accessionQ5TM17
Proteomes
Organism-specific databases
Subcellular Location
UniProt Annotation
GO Annotation
Note: Can translocate to the cytoplasm in the presence of MX1.
Keywords
- Cellular component
PTM/Processing
Features
Showing features for initiator methionine, modified residue, chain, cross-link.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Initiator methionine | 1 | Removed | ||||
Sequence: M | ||||||
Modified residue | 2 | N-acetylalanine | ||||
Sequence: A | ||||||
Chain | PRO_0000055072 | 2-428 | Spliceosome RNA helicase DDX39B | |||
Sequence: AENDVDNELLDYEDDEVETAAGGDGAEAPAKKDVKGSYVSIHSSGFRDFLLKPELLRAIVDCGFEHPSEVQHECIPQAILGMDVLCQAKSGMGKTAVFVLATLQQLEPVTGQVSVLVMCHTRELAFQISKEYERFSKYMPNVKVAVFFGGLSIKKDEEVLKKNCPHIVVGTPGRILALARNKSLNLKHIKHFILDECDKMLEQLDMRRDVQEIFRMTPHEKQVMMFSATLSKEIRPVCRKFMQDPMEIFVDDETKLTLHGLQQYYVKLKDNEKNRKLFDLLDVLEFNQVVIFVKSVQRCIALAQLLVEQNFPAIAIHRGMPQEERLSRYQQFKDFQRRILVATNLFGRGMDIERVNIAFNYDMPEDSDTYLHRVARAGRFGTKGLAITFVSDENDAKILNDVQDRFEVNISELPDEIDISSYIEQTR | ||||||
Modified residue | 36 | N6-acetyllysine; alternate | ||||
Sequence: K | ||||||
Cross-link | 36 | Glycyl lysine isopeptide (Lys-Gly) (interchain with G-Cter in SUMO2); alternate | ||||
Sequence: K | ||||||
Modified residue | 38 | Phosphoserine | ||||
Sequence: S | ||||||
Modified residue | 41 | Phosphoserine | ||||
Sequence: S | ||||||
Modified residue | 172 | Phosphothreonine | ||||
Sequence: T |
Keywords
- PTM
Proteomic databases
Expression
Gene expression databases
Interaction
Subunit
Homodimer, and heterodimer with DDX39A. DDX39B interacts with the THO subcomplex to form the THO-DDX39B complex which multimerizes into a 28-subunit tetrameric assembly. Component of the transcription/export (TREX) complex at least composed of ALYREF/THOC4, DDX39B, SARNP/CIP29, CHTOP and the THO subcomplex; in the complex interacts with THOC2. THOC1-THOC2-THOC3-DDX39B subcomplex is sufficient for the interaction with export factor NXF1-NXT1. TREX seems to have a dynamic structure involving ATP-dependent remodeling. Within the TREX complex bridges ALYREF/THOC4 and the THO subcomplex, and, in a ATP-dependent manner, ALYREF/THOC4 and SARNP/CIP29. Component of the spliceosome. Interacts directly with U2AF2. Interacts with RBM8A, RNPS1 and SRRM1, FYTTD1/UIF, THOC1, MX1 and POLDIP3. Interacts with LUZP4. Interacts with SARNP/CIP29 (via the C-terminal domain); the interaction is direct and facilitates RNA binding of DDX39B.
Protein-protein interaction databases
Structure
Family & Domains
Features
Showing features for compositional bias, region, motif, domain.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Compositional bias | 1-22 | Acidic residues | ||||
Sequence: MAENDVDNELLDYEDDEVETAA | ||||||
Region | 1-31 | Disordered | ||||
Sequence: MAENDVDNELLDYEDDEVETAAGGDGAEAPA | ||||||
Motif | 45-73 | Q motif | ||||
Sequence: SGFRDFLLKPELLRAIVDCGFEHPSEVQH | ||||||
Domain | 76-249 | Helicase ATP-binding | ||||
Sequence: IPQAILGMDVLCQAKSGMGKTAVFVLATLQQLEPVTGQVSVLVMCHTRELAFQISKEYERFSKYMPNVKVAVFFGGLSIKKDEEVLKKNCPHIVVGTPGRILALARNKSLNLKHIKHFILDECDKMLEQLDMRRDVQEIFRMTPHEKQVMMFSATLSKEIRPVCRKFMQDPMEI | ||||||
Motif | 196-199 | DECD box | ||||
Sequence: DECD | ||||||
Domain | 261-422 | Helicase C-terminal | ||||
Sequence: GLQQYYVKLKDNEKNRKLFDLLDVLEFNQVVIFVKSVQRCIALAQLLVEQNFPAIAIHRGMPQEERLSRYQQFKDFQRRILVATNLFGRGMDIERVNIAFNYDMPEDSDTYLHRVARAGRFGTKGLAITFVSDENDAKILNDVQDRFEVNISELPDEIDISS |
Domain
The helicase C-terminal domain mediates interaction with ALYREF/THOC4.
Sequence similarities
Belongs to the DEAD box helicase family. DECD subfamily.
Phylogenomic databases
Family and domain databases
Sequence
- Sequence statusComplete
- Length428
- Mass (Da)48,991
- Last updated2004-12-21 v1
- Checksum7A55167BF576FB6F
Computationally mapped potential isoform sequences
There is 1 potential isoform mapped to this entry
Entry | Entry name | Gene name | Length | ||
---|---|---|---|---|---|
A0A5F8AKV1 | A0A5F8AKV1_MACMU | DDX39B | 350 |
Features
Showing features for compositional bias.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Compositional bias | 1-22 | Acidic residues | ||||
Sequence: MAENDVDNELLDYEDDEVETAA |
Keywords
- Technical term
Sequence databases
Nucleotide Sequence | Protein Sequence | Molecule Type | Status | |
---|---|---|---|---|
AB128049 EMBL· GenBank· DDBJ | BAD69728.1 EMBL· GenBank· DDBJ | Genomic DNA |