1kf9 | pdb_00001kf9
PHAGE DISPLAY DERIVED VARIANT OF HUMAN GROWTH HORMONE COMPLEXED WITH TWO COPIES OF THE EXTRACELLULAR DOMAIN OF ITS RECEPTOR
Structural highlights
DiseaseSOMA_HUMAN Defects in GH1 are a cause of growth hormone deficiency isolated type 1A (IGHD1A) [MIM:262400; also known as pituitary dwarfism I. IGHD1A is an autosomal recessive deficiency of GH which causes short stature. IGHD1A patients have an absence of GH with severe dwarfism and often develop anti-GH antibodies when given exogenous GH.[1] Defects in GH1 are a cause of growth hormone deficiency isolated type 1B (IGHD1B) [MIM:612781; also known as dwarfism of Sindh. IGHD1B is an autosomal recessive deficiency of GH which causes short stature. IGHD1B patients have low but detectable levels of GH. Dwarfism is less severe than in IGHD1A and patients usually respond well to exogenous GH. Defects in GH1 are the cause of Kowarski syndrome (KWKS) [MIM:262650; also known as pituitary dwarfism VI.[2] [3] [4] Defects in GH1 are a cause of growth hormone deficiency isolated type 2 (IGHD2) [MIM:173100. IGHD2 is an autosomal dominant deficiency of GH which causes short stature. Clinical severity is variable. Patients have a positive response and immunologic tolerance to growth hormone therapy. FunctionSOMA_HUMAN Plays an important role in growth control. Its major role in stimulating body growth is to stimulate the liver and other tissues to secrete IGF-1. It stimulates both the differentiation and proliferation of myoblasts. It also stimulates amino acid uptake and protein synthesis in muscle and other tissues. 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 PubMedThe structure of the ternary complex between the phage display- optimized, high-affinity Site 1 variant of human growth hormone (hGH) and two copies of the extracellular domain (ECD) of the hGH receptor (hGHR) has been determined at 2.6 A resolution. There are widespread and significant structural differences compared to the wild-type ternary hGH hGHR complex. The hGH variant (hGH(v)) contains 15 Site 1 mutations and binds>10(2) tighter to the hGHR ECD (hGH(R1)) at Site 1. It is biologically active and specific to hGHR. The hGH(v) Site 1 interface is somewhat smaller and 20% more hydrophobic compared to the wild-type (wt) counterpart. Of the ten hormone-receptor H-bonds in the site, only one is the same as in the wt complex. Additionally, several regions of hGH(v) structure move up to 9A in forming the interface. The contacts between the C-terminal domains of two receptor ECDs (hGH(R1)- hGH(R2)) are conserved; however, the large changes in Site 1 appear to cause global changes in the domains of hGH(R1) that affect the hGH(v)-hGH(R2) interface indirectly. This coupling is manifested by large changes in the conformation of groups participating in the Site 2 interaction and results in a structure for the site that is reorganized extensively. The hGH(v)- hGH(R2) interface contains seven H-bonds, only one of which is found in the wt complex. Several groups on hGH(v) and hGH(R2) undergo conformational changes of up to 8 A. Asp116 of hGH(v) plays a central role in the reorganization of Site 2 by forming two new H-bonds to the side-chains of Trp104(R2) and Trp169(R2), which are the key binding determinants of the receptor. The fact that a different binding solution is possible for Site 2, where there were no mutations or binding selection pressures, indicates that the structural elements found in these molecules possess an inherent functional plasticity that enables them to bind to a wide variety of binding surfaces. Structure of a phage display-derived variant of human growth hormone complexed to two copies of the extracellular domain of its receptor: evidence for strong structural coupling between receptor binding sites.,Schiffer C, Ultsch M, Walsh S, Somers W, de Vos AM, Kossiakoff A J Mol Biol. 2002 Feb 15;316(2):277-89. PMID:11851338[5] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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