1NQ1

TR Receptor Mutations Conferring Hormone Resistance and Reduced Corepressor Release Exhibit Decreased Stability in the Nterminal LBD

Summary for 1NQ1

• Entry DOI: 10.2210/pdb1nq1/pdb
• Descriptor: Thyroid hormone receptor beta-1, [4-(4-HYDROXY-3-IODO-PHENOXY)-3,5-DIIODO-PHENYL]-ACETIC ACID, ARSENIC (3 entities in total)
• Functional Keywords: alpha helical, ligand binding domain, hormone-growth factor receptor complex, hormone/growth factor receptor
• Biological source: Homo sapiens (human)
• Cellular location: Nucleus: P10828
• Total number of polymer chains: 1
• Total formula weight: 30413.03

Authors

Huber, B.R.,Desclozeaux, M.,West, B.L.,Cunha-Lima, S.T.,Nguyen, H.T.,Baxter, J.D.,Ingraham, H.A.,Fletterick, R.J. (deposition date: 2003-01-20, release date: 2003-04-15, Last modification date: 2024-04-03)

Primary citation

Huber, B.R.,Desclozeaux, M.,West, B.L.,Cunha-Lima, S.T.,Nguyen, H.T.,Baxter, J.D.,Ingraham, H.A.,Fletterick, R.J.
Thyroid hormone receptor-beta mutations conferring hormone resistance and reduced corepressor release exhibit decreased stability in the N-terminal ligand-binding domain
Mol.Endocrinol., 17:107-116, 2003

PubMed Abstract: Resistance to thyroid hormone (RTH) syndrome is associated with mutations in the human thyroid hormone receptor-beta (hTRbeta), many of which show marked reduction in hormone binding. Here, we investigated the structural consequences of two RTH mutants (A234T and R243Q), residing in the flexible N-terminal portion of the ligand binding domain (LBD), which exhibit modestly reduced hormone binding with impaired release of corepressor. X-ray crystallography analyses revealed that these two RTH mutants modulate the position of this flexible region by either altering the movement of helix 1 (A234T) or disrupting a salt bridge (R243Q). The subsequent increased flexibility and mobility in regions after the two sites of mutation coincided with a disorganized LBD. Consistent with this finding, the ability of these mutant N-terminal regions (234-260) to recruit the remaining LBD was decreased in a ligand-dependent helix assembly assay. Collectively, these data suggest that structural information imparted by the flexible segment in the N-terminal LBD is critical for overall stability of the LBD. Thus, these structural analyses provide mechanistic insight into the etiology of RTH disease in human TRbeta mutants that exhibit hormone binding with decreased ligand-dependent corepressor release.

PubMed: 12511610
DOI: 10.1210/me.2002-0097

Experimental method

X-RAY DIFFRACTION (2.9 Å)