"A zinc finger is a small protein structural motif that is characterized by the coordination of one or more zinc ions in order to stabilize the fold."
http://en.wikipedia.org/wiki/Zinc_finger
Zinc fingers bind DNA and act as transcription factors. This zinc finger binds a zinc ion through two cysteine and two histidine residues.

This zinc finger model is based on PDB model 3IUF:
http://www.rcsb.org/pdb/explore/explore.do?structureId=3iuf
Model created using VMD:
http://www.ks.uiuc.edu/Research/vmd/

Successfully printed by a Replicator 2 in PLA using MakerWare(TM) 2.4.1.24, standard resolution (3 shells, 25% infill), with raft and supports.

Representations for hand coloring the model are shown.