PMID: 10089305 , Related PDB ids: 2A2G, 2A2U

Authors:

Chaudhuri BN, Kleywegt GJ, Bjorkman J, Lehman-McKeeman LD, Oliver JD, Jones TA

Title:

The structures of alpha 2u-globulin and its complex with a hyaline droplet inducer.

Journal:

Acta Crystallogr D Biol Crystallogr. 1999 Apr;55(Pt 4):753-62.

Abstract:

Alpha 2u-globulin (A2U) is the major urinary protein excreted by adult male rats. The structure of a monoclinic crystal form of A2U was reported in 1992 [Bocskei et al. (1992). Nature (London), 360, 186-188]. The structures of an orthorhombic crystal form of A2U at 2. 5 A resolution (refined to an R factor of 0.248; Rfree = 0.264) and of a complex between A2U and d-limonene 1,2-epoxide (DLO) at 2.9 A resolution (R factor = 0.248; Rfree = 0.260) are presented here. DLO is one of a diverse group of chemicals which cause a male rat-specific renal carcinogenesis called hyaline-droplet nephropathy. The rate-determining step in the development of this disorder is the binding of the toxin to A2U. Comparison of the cavities in A2U and in the corresponding mouse urinary protein (MUP) reveal that the former is tailor-made for small oval hydrophobic ligands such as DLO. The cavity in MUP is more shallow and elongated and cannot easily accommodate such ligands.