Editing Steroid hormone receptor (section)

==== Structure ====

Intracellular steroid hormone receptors share a common structure of four units that are functionally homologous, so-called "domains":

# ''Variable domain'': It begins at the N-terminal and is the most variable domain between the different receptors.
# ''DNA binding domain'': This centrally located highly conserved DNA binding domain (DBD) consists of two non-repetitive globular motifs<ref name="pmid8221895">{{PDB|1HCQ}}; {{cite journal | vauthors = Schwabe JW, Chapman L, Finch JT, Rhodes D | title = The crystal structure of the estrogen receptor DNA-binding domain bound to DNA: how receptors discriminate between their response elements | journal = Cell | volume = 75 | issue = 3 | pages = 567–78 | date = Nov 1993 | pmid = 8221895 | doi = 10.1016/0092-8674(93)90390-C | s2cid = 20795587 }}</ref> where zinc is coordinated with four [[cysteine]] and no [[histidine]] residues. Their secondary and tertiary structure is distinct from that of classic [[zinc finger]]s.<ref name="pmid3283939">{{cite journal | vauthors = Evans RM | title = The steroid and thyroid hormone receptor superfamily | journal = Science | volume = 240 | issue = 4854 | pages = 889–95 | date = May 1988 | pmid = 3283939 | pmc = 6159881 | doi = 10.1126/science.3283939 | bibcode = 1988Sci...240..889E }}</ref> This region controls which gene will be activated. On DNA it interacts with the [[hormone response element]] (HRE).
# ''Hinge region'': This area controls the movement of the receptor to the nucleus.
# ''Hormone binding domain'': The moderately conserved [[ligand]]-binding domain (LBD) can include a [[nuclear localization signal]], amino-acid sequences capable of binding chaperones and parts of dimerization interfaces. Such receptors are closely related to [[Chaperone (protein)|chaperone]]s (namely heat shock proteins [[hsp90]] and [[FKBP4|hsp56]]), which are required to maintain their inactive (but receptive) cytoplasmic [[Protein structure|conformation]]. At the end of this domain is the C-terminal. The terminal connects the molecule to its pair in the homodimer or heterodimer. It may affect the magnitude of the response.