Structural highlights
Function
[SHBG_HUMAN] Functions as an androgen transport protein, but may also be involved in receptor mediated processes. Each dimer binds one molecule of steroid. Specific for 5-alpha-dihydrotestosterone, testosterone, and 17-beta-estradiol. Regulates the plasma metabolic clearance rate of steroid hormones by controlling their plasma concentration.
Evolutionary Conservation
Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
Publication Abstract from PubMed
Human sex hormone-binding globulin (SHBG) transports sex steroids in blood and regulates their access to target tissues. In biological fluids, SHBG exists as a homodimer and each monomer comprises two laminin G-like domains (G domains). The crystal structure of the N-terminal G domain of SHBG in complex with 5alpha-dihydrotestosterone at 1.55 A resolution reveals both the architecture of the steroid-binding site and the quaternary structure of the dimer. We also show that G domains have jellyroll topology and are structurally related to pentraxin. In each SHBG monomer, the steroid intercalates into a hydrophobic pocket within the beta-sheet sandwich. The steroid and a 20 A distant calcium ion are not located at the dimer interface. Instead, two separate steroid-binding pockets and calcium-binding sites exist per dimer. The structure displays intriguing disorder for loop segment Pro130-Arg135. In all other jellyroll proteins, this loop is well ordered. If modelled accordingly, it covers the steroid-binding site and could thereby regulate access of ligands to the binding pocket.
Crystal structure of human sex hormone-binding globulin: steroid transport by a laminin G-like domain.,Grishkovskaya I, Avvakumov GV, Sklenar G, Dales D, Hammond GL, Muller YA EMBO J. 2000 Feb 15;19(4):504-12. PMID:10675319[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Grishkovskaya I, Avvakumov GV, Sklenar G, Dales D, Hammond GL, Muller YA. Crystal structure of human sex hormone-binding globulin: steroid transport by a laminin G-like domain. EMBO J. 2000 Feb 15;19(4):504-12. PMID:10675319 doi:10.1093/emboj/19.4.504
