Model of the Leucine Rich Repeat (LRR) domain from human NLRP1 protein in cartoon form. 
"A leucine-rich repeat (LRR) is a protein structural motif that forms an α/β horseshoe fold" 
http://en.wikipedia.org/wiki/Leucine-rich_repeat 
NACHT, LRR and PYD domains-containing protein 1 (NLRP1) is a protein that in humans is encoded by the NLRP1 gene: 
http://en.wikipedia.org/wiki/NLRP1 
Model based on the Protein Data Bank entry 4IM6: 
http://www.rcsb.org/pdb/explore/explore.do?structureId=4im6 
STL file created using VMD: 
http://www.ks.uiuc.edu/Research/vmd/