1ixa: Difference between revisions

[[Image:1ixa.gif|left|200px]]<br /><applet load="1ixa" size="350" color="white" frame="true" align="right" spinBox="true"  

The three-dimensional structure of the first epidermal growth factor (EGF)-like module from human factor IX has been determined in solution using two-dimensional nuclear magnetic resonance (in the absence of calcium and at pH 4.5). The structure was found to resemble closely that of EGF and the homologous transforming growth factor-alpha (TGF-alpha). Residues 60-65 form an antiparallel beta-sheet with residues 68-73. In the C-terminal subdomain a type II beta-turn is found between residues 74 and 77 and a five-residue turn is found between residues 79 and 83. Glu 78 and Leu 84 pair in an antiparallel beta-sheet conformation. In the N-terminal region a loop is found between residues 50 and 55 such that the side chains of both are positioned above the face of the beta-sheet. Residues 56-60 form a turn that leads into the first strand of the beta-sheet. Whereas the global fold closely resembles that of EGF, the N-terminal residues of the module (46-49) do not form a beta-strand but are ill-defined in the structure, probably due to the local flexibility of this region. The structure is discussed with reference to recent site-directed mutagenesis data, which have identified certain conserved residues as ligands for calcium.

1IXA is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1IXA OCA].  

[[Category: Brownlee, G G.]]

[[Category: Campbell, I D.C.]]

[[Category: Hanford, P A.]]

[[Category: Harvey, T S.]]

[[Category: Norman, D G.]]

[[Category: Tse, A G.D.]]

''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 13:16:39 2008''