PWI

PWI, domain in splicing factors

• SMART accession number: SM00311
• Interpro abstract (IPR002483):

  The PWI domain, named after a highly conserved PWI tri-peptide located within its N-terminal region, is a ~80 amino acid module, which is found either at the N terminus or at the C terminus of eukaryotic proteins involved in pre-mRNA processing [(PUBMED:10322432)]. It is generally found in association with other domains such as RRM and RS. The PWI domain is a RNA/DNA-binding domain that has an equal preference for single- and double-stranded nucleic acids and is likely to have multiple important functions in pre-mRNA processing [(PUBMED:12600940)]. Proteins containing this domain include the SR-related nuclear matrix protein of 160kDa (SRm160) splicing and 3'-end cleavage-stimulatory factor, and the mammalian splicing factor PRP3.

  The PWI domain is a soluble, globular and independently folded domain which consists of a four-helix bundle, with structured N- and C-terminal elements [(PUBMED:12600940)].

• GO process: mRNA processing (GO:0006397)

There are 170 PWI domains in 170 proteins in SMART's nrdb database.

Literature (relevant references for this domain)

Primary literature is listed below; Automatically-derived, secondary literature is also avaliable.

• Szymczyna BR et al.
• Structure and function of the PWI motif: a novel nucleic acid-binding domain that facilitates pre-mRNA processing.
• Genes Dev. 2003; 17: 461-75

The PWI motif is a highly conserved domain of unknown function in the SRm160 splicing and 3'-end cleavage-stimulatory factor, as well as in several other known or putative pre-mRNA processing components. We show here that the PWI motif is a new type of RNA/DNA-binding domain that has an equal preference for single- and double-stranded nucleic acids. Deletion of the motif prevents SRm160 from binding RNA and stimulating 3'-end cleavage, and its substitution with a heterologous RNA-binding domain restores these functions. The NMR solution structure of the SRm160-PWI motif reveals a novel, four-helix bundle and represents the first example of an alpha-helical fold that can bind single-stranded (ss)RNA. Structure-guided mutagenesis indicates that the same surface is involved in RNA and DNA binding and requires the cooperative action of a highly conserved, adjacent basic region. Thus, the PWI motif is a novel type of nucleic acid-binding domain that likely has multiple important functions in pre-mRNA processing, including SRm160-dependent stimulation of 3'-end formation.

Structure (3D structures containing this domain)

3D Structures of PWI domains in PDB

PDB code	Title
1mp1	Solution structure of the pwi motif from srm160
1x4q	Solution structure of pwi domain in u4/u6 small nuclear ribonucleoprotein prp3(hprp3)

Links (links to other resources describing this domain)

• INTERPRO: IPR002483