4nu6 is a 2 chain structure with sequence from Pseudomonas stutzeri. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
↑ Costas AM, White AK, Metcalf WW. Purification and characterization of a novel phosphorus-oxidizing enzyme from Pseudomonas stutzeri WM88. J Biol Chem. 2001 May 18;276(20):17429-36. doi: 10.1074/jbc.M011764200. Epub 2001 , Feb 22. PMID:11278981 doi:http://dx.doi.org/10.1074/jbc.M011764200