2h1k: Difference between revisions

[[Image:2h1k.gif|left|200px]]<br /><applet load="2h1k" size="350" color="white" frame="true" align="right" spinBox="true"  

Pancreatic and duodenal homeobox 1 (Pdx1) is a homeodomain transcription factor belonging to the ParaHox family. Pdx1 plays an essential role in pancreatic endocrine and exocrine cell development and maintenance of adult islet beta-cell function. Mutations in the human pdx1 gene are linked to an early onset form of non-insulin-dependent diabetes mellitus, MODY-4. We demonstrate that the homeodomain reproduces the binding specificity of the full-length protein. We report the 2.4 A resolution crystal structure of the homeodomain bound to a target DNA. The two Pdx1/DNA complexes in the asymmetric unit display conformational differences: in the DNA curvature, the orientation of the homeodomain in the major groove, and the order of the N-terminal arm. Comparing the two complexes indicates invariant protein-DNA contacts, and variant contacts that are unique to each binding orientation. An induced fit model is proposed that depends on the DNA conformation and provides a mechanism for nonlocal contributions to binding specificity.

2H1K is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Mesocricetus_auratus Mesocricetus auratus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2H1K OCA].  

Structural basis for induced fit mechanisms in DNA recognition by the Pdx1 homeodomain., Longo A, Guanga GP, Rose RB, Biochemistry. 2007 Mar 20;46(11):2948-57. Epub 2007 Feb 23. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=17315980 17315980]

[[Category: Guanga, G P.]]

[[Category: Rose, R B.]]

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