4pti is a 1 chain structure with sequence from Bovin. This structure supersedes the now removed PDB entries 3pti and 2pti. The October 2011 RCSB PDB Molecule of the Month feature on PDB Pioneers by David Goodsell is 10.2210/rcsb_pdb/mom_2011_10. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.