4xu5 is a 1 chain structure with sequence from Mycolicibacterium vanbaalenii PYR-1. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
↑ Ren R, Zhou X, He Y, Ke M, Wu J, Liu X, Yan C, Wu Y, Gong X, Lei X, Yan SF, Radhakrishnan A, Yan N. PROTEIN STRUCTURE. Crystal structure of a mycobacterial Insig homolog provides insight into how these sensors monitor sterol levels. Science. 2015 Jul 10;349(6244):187-91. doi: 10.1126/science.aab1091. PMID:26160948 doi:http://dx.doi.org/10.1126/science.aab1091