The paraspeckle component 1 (PSPC1) and non-POU-domain-containing 
octamer-binding protein (NONO) heterodimer is an essential structural component 
of paraspeckles, ribonucleoprotein bodies found in the interchromatin space of 
mammalian cell nuclei. PSPC1 and NONO both belong to the Drosophila behaviour 
and human splicing (DBHS) protein family, which has been implicated in many 
aspects of RNA processing. A heterodimer of the core DBHS conserved region of 
PSPC1 and NONO comprising two tandemly arranged RNA-recognition motifs (RRMs), a 
NONA/paraspeckle (NOPS) domain and part of a predicted coiled-coil domain has 
been crystallized in space group C2, with unit-cell parameters a = 90.90, b = 
67.18, c = 94.08 Å, β = 99.96°. The crystal contained one heterodimer in the 
asymmetric unit and diffracted to 1.9 Å resolution using synchrotron radiation.