1MP1: Solution structure of the PWI motif from SRm160

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.
PDB ID: 1MP1Download
MMDB ID: 24622
PDB Deposition Date: 2002/9/11
Updated in MMDB: 2007/11
Experimental Method:
solution nmr
Source Organism:
Similar Structures:
Molecular Components in 1MP1
Label Count Molecule
Protein (1 molecule)
Ser/arg-related Nuclear Matrix Protein(Gene symbol: SRRM1)
Molecule annotation
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Citing MMDB