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1am9
From Proteopedia
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[[Image:1am9.gif|left|200px]] | [[Image:1am9.gif|left|200px]] | ||
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'''HUMAN SREBP-1A BOUND TO LDL RECEPTOR PROMOTER''' | '''HUMAN SREBP-1A BOUND TO LDL RECEPTOR PROMOTER''' | ||
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[[Category: Burley, S K.]] | [[Category: Burley, S K.]] | ||
[[Category: Parraga, A.]] | [[Category: Parraga, A.]] | ||
| - | [[Category: | + | [[Category: Basic-helix-loop-helix-leucine zipper]] |
| - | [[Category: | + | [[Category: Srebp]] |
| - | [[Category: | + | [[Category: Sterol regulatory element binding protein]] |
| - | + | [[Category: Transcription factor]] | |
| - | [[Category: | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Fri May 2 10:26:34 2008'' |
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| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | |
Revision as of 07:26, 2 May 2008
HUMAN SREBP-1A BOUND TO LDL RECEPTOR PROMOTER
Overview
BACKGROUND: The sterol regulatory element binding proteins (SREBPs) are helix-loop-helix transcriptional activators that control expression of genes encoding proteins essential for cholesterol biosynthesis/uptake and fatty acid biosynthesis. Unlike helix-loop-helix proteins that recognize symmetric E-boxes (5'-CANNTG-3'), the SREBPs have a tyrosine instead of a conserved arginine in their basic regions. This difference allows recognition of an asymmetric sterol regulatory element (StRE, 5'-ATCACCCAC-3'). RESULTS: The 2.3 A resolution co-crystal structure of the DNA-binding portion of SREBP-1a bound to an StRE reveals a quasi-symmetric homodimer with an asymmetric DNA-protein interface. One monomer binds the E-box half site of the StRE (5'-ATCAC-3') using sidechain-base contacts typical of other helix-loop-helix proteins. The non-E-box half site (5'-GTGGG-3') is recognized through entirely different protein-DNA contacts. CONCLUSIONS: Although the SREBPs are structurally similar to the E-box-binding helix-loop-helix proteins, the Arg-->Tyr substitution yields dramatically different DNA-binding properties that explain how they recognize StREs and regulate expression of genes important for membrane biosynthesis.
About this Structure
1AM9 is a Single protein structure of sequence from Homo sapiens. Full crystallographic information is available from OCA.
Reference
Co-crystal structure of sterol regulatory element binding protein 1a at 2.3 A resolution., Parraga A, Bellsolell L, Ferre-D'Amare AR, Burley SK, Structure. 1998 May 15;6(5):661-72. PMID:9634703 Page seeded by OCA on Fri May 2 10:26:34 2008
