DNA binding domain

The DNA binding domain (DBD) is located in the central core of the receptor and consists of DNA binding zinc fingers which are two outloops of protein sequences, each held in place by four conserved cysteine residues that coordinate with a zinc ion (Freedman etal. 1988). This motif is well conserved for members of the steroid receptor family such that information on the structure of this domain of the AR can be inferred from analysis of the equivalent domain of the other steroid receptors. The crystal structures of the glucocorticoid and estrogen receptor zinc fingers bound to their response elements have been solved (Luisi etal. 1991; Schwabe etal. 1993). Sequence specific DNA interactions occur through an a-helix which lies in the major groove of the DNA. The most important amino acids in this regard are the same for both the androgen and glucocorticoid receptors. As other domains of the AR, the DBD also serves as an interface for binding other factors. A 60 kDa polypeptide that shares N-terminal homology to a calcium binding protein, calreticulin, has been shown to bind the sequence KXFFKR in the DBD of the AR to inhibit DNA binding and transactivation by the receptor (Dedhar et al. 1994). Calreticulin is therefore a regulator of AR action and recent studies show that it is a receptor for nuclear export of proteins (Holaska etal. 2001). Thus the DBD of the AR contains a sequence for nuclear export, but how this functions in the signaling pathway of the receptor is not clear.

Hair Loss Prevention

Hair Loss Prevention

The best start to preventing hair loss is understanding the basics of hair what it is, how it grows, what system malfunctions can cause it to stop growing. And this ebook will cover the bases for you. Note that the contents here are not presented from a medical practitioner, and that any and all dietary and medical planning should be made under the guidance of your own medical and health practitioners. This content only presents overviews of hair loss prevention research for educational purposes and does not replace medical advice from a professional physician.

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