Q5TM17 · DX39B_MACMU

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

Features

Showing features for binding site.

TypeIDPosition(s)Description
Binding site89-96ATP (UniProtKB | ChEBI)

GO annotations

AspectTerm
Cellular Componentcytoplasm
Cellular Componentnuclear speck
Cellular Componentspliceosomal complex
Molecular FunctionATP binding
Molecular FunctionATP hydrolysis activity
Molecular FunctionmRNA binding
Molecular FunctionRNA helicase activity
Biological ProcessmRNA export from nucleus
Biological ProcessmRNA splicing, via spliceosome

Keywords

Enzyme and pathway databases

Names & Taxonomy

Protein names

  • Recommended name
    Spliceosome RNA helicase DDX39B
  • EC number
  • Alternative names
    • 56 kDa U2AF65-associated protein
    • DEAD box protein UAP56

Gene names

    • Name
      DDX39B
    • Synonyms
      BAT1, UAP56

Organism names

  • Taxonomic identifier
  • Taxonomic lineage
    Eukaryota > Metazoa > Chordata > Craniata > Vertebrata > Euteleostomi > Mammalia > Eutheria > Euarchontoglires > Primates > Haplorrhini > Catarrhini > Cercopithecidae > Cercopithecinae > Macaca

Accessions

  • Primary accession
    Q5TM17

Proteomes

Organism-specific databases

Subcellular Location

Nucleus
Nucleus speckle
Cytoplasm
Note: Can translocate to the cytoplasm in the presence of MX1.

Keywords

PTM/Processing

Features

Showing features for initiator methionine, modified residue, chain, cross-link.

TypeIDPosition(s)Description
Initiator methionine1Removed
Modified residue2N-acetylalanine
ChainPRO_00000550722-428Spliceosome RNA helicase DDX39B
Modified residue36N6-acetyllysine; alternate
Cross-link36Glycyl lysine isopeptide (Lys-Gly) (interchain with G-Cter in SUMO2); alternate
Modified residue38Phosphoserine
Modified residue41Phosphoserine
Modified residue172Phosphothreonine

Keywords

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.

TypeIDPosition(s)Description
Compositional bias1-22Acidic residues
Region1-31Disordered
Motif45-73Q motif
Domain76-249Helicase ATP-binding
Motif196-199DECD box
Domain261-422Helicase C-terminal

Domain

The helicase C-terminal domain mediates interaction with ALYREF/THOC4.

Sequence similarities

Phylogenomic databases

Family and domain databases

Sequence

  • Sequence status
    Complete
  • Length
    428
  • Mass (Da)
    48,991
  • Last updated
    2004-12-21 v1
  • Checksum
    7A55167BF576FB6F
MAENDVDNELLDYEDDEVETAAGGDGAEAPAKKDVKGSYVSIHSSGFRDFLLKPELLRAIVDCGFEHPSEVQHECIPQAILGMDVLCQAKSGMGKTAVFVLATLQQLEPVTGQVSVLVMCHTRELAFQISKEYERFSKYMPNVKVAVFFGGLSIKKDEEVLKKNCPHIVVGTPGRILALARNKSLNLKHIKHFILDECDKMLEQLDMRRDVQEIFRMTPHEKQVMMFSATLSKEIRPVCRKFMQDPMEIFVDDETKLTLHGLQQYYVKLKDNEKNRKLFDLLDVLEFNQVVIFVKSVQRCIALAQLLVEQNFPAIAIHRGMPQEERLSRYQQFKDFQRRILVATNLFGRGMDIERVNIAFNYDMPEDSDTYLHRVARAGRFGTKGLAITFVSDENDAKILNDVQDRFEVNISELPDEIDISSYIEQTR

Computationally mapped potential isoform sequences

There is 1 potential isoform mapped to this entry

View all
EntryEntry nameGene nameLength
A0A5F8AKV1A0A5F8AKV1_MACMUDDX39B350

Features

Showing features for compositional bias.

TypeIDPosition(s)Description
Compositional bias1-22Acidic residues

Keywords

Sequence databases

Nucleotide SequenceProtein SequenceMolecule TypeStatus
AB128049
EMBL· GenBank· DDBJ
BAD69728.1
EMBL· GenBank· DDBJ
Genomic DNA

Genome annotation databases

Similar Proteins

Disclaimer

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