1a93
From Proteopedia
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|PDB= 1a93 |SIZE=350|CAPTION= <scene name='initialview01'>1a93</scene> | |PDB= 1a93 |SIZE=350|CAPTION= <scene name='initialview01'>1a93</scene> | ||
|SITE= | |SITE= | ||
| - | |LIGAND= <scene name='pdbligand=ACE:ACETYL+GROUP'>ACE</scene> | + | |LIGAND= <scene name='pdbligand=ACE:ACETYL+GROUP'>ACE</scene>, <scene name='pdbligand=NH2:AMINO+GROUP'>NH2</scene> |
|ACTIVITY= | |ACTIVITY= | ||
|GENE= | |GENE= | ||
| + | |DOMAIN= | ||
| + | |RELATEDENTRY=[[2a93|2A93]] | ||
| + | |RESOURCES=<span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1a93 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1a93 OCA], [http://www.ebi.ac.uk/pdbsum/1a93 PDBsum], [http://www.rcsb.org/pdb/explore.do?structureId=1a93 RCSB]</span> | ||
}} | }} | ||
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==Overview== | ==Overview== | ||
The oncoprotein c-Myc (a member of the helix-loop-helix-leucine zipper (b-HLH-LZ) family of transcription factors) must heterodimerize with the b-HLH-LZ Max protein to bind DNA and activate transcription. It has been shown that the LZ domains of the c-Myc and Max proteins specifically form a heterodimeric LZ at 20 degreesC and neutral pH. This suggests that the LZ domains of the c-Myc and Max proteins are playing an important role in the heterodimerization of the corresponding gene products in vivo. Initially, to gain an insight into the energetics of heterodimerization, we studied the stability of N-terminal disulfide-linked versions of the c-Myc and Max homodimeric LZs and c-Myc-Max heterodimeric LZ by fitting the temperature-induced denaturation curves monitored by circular dichroism spectroscopy. The c-Myc LZ does not homodimerize (as previously reported) and the c-Myc-Max heterodimeric LZ is more stable than the Max homodimeric LZ at 20 degreesC and pH 7.0. In order to determine the critical interhelical interactions responsible for the molecular recognition between the c-Myc and Max LZs, the solution structure of the disulfide-linked c-Myc-Max heterodimeric LZ was solved by two-dimensional 1H-NMR techniques at 25 degreesC and pH 4.7. Both LZs are alpha-helical and the tertiary structure depicts the typical left-handed super-helical twist of a two-stranded parallel alpha-helical coiled-coil. A buried salt bridge involving a histidine on the Max LZ and two glutamate residues on the c-Myc LZ is observed at the interface of the heterodimeric LZ. A buried H-bond between an asparagine side-chain and a backbone carbonyl is also observed. Moreover, evidence for e-g interhelical salt bridges is reported. These specific interactions give insights into the preferential heterodimerization process of the two LZs. The low stabilities of the Max homodimeric LZ and the c-Myc-Max heterodimeric LZ as well as the specific interactions observed are discussed with regard to regulation of transcription in this family of transcription factors. | The oncoprotein c-Myc (a member of the helix-loop-helix-leucine zipper (b-HLH-LZ) family of transcription factors) must heterodimerize with the b-HLH-LZ Max protein to bind DNA and activate transcription. It has been shown that the LZ domains of the c-Myc and Max proteins specifically form a heterodimeric LZ at 20 degreesC and neutral pH. This suggests that the LZ domains of the c-Myc and Max proteins are playing an important role in the heterodimerization of the corresponding gene products in vivo. Initially, to gain an insight into the energetics of heterodimerization, we studied the stability of N-terminal disulfide-linked versions of the c-Myc and Max homodimeric LZs and c-Myc-Max heterodimeric LZ by fitting the temperature-induced denaturation curves monitored by circular dichroism spectroscopy. The c-Myc LZ does not homodimerize (as previously reported) and the c-Myc-Max heterodimeric LZ is more stable than the Max homodimeric LZ at 20 degreesC and pH 7.0. In order to determine the critical interhelical interactions responsible for the molecular recognition between the c-Myc and Max LZs, the solution structure of the disulfide-linked c-Myc-Max heterodimeric LZ was solved by two-dimensional 1H-NMR techniques at 25 degreesC and pH 4.7. Both LZs are alpha-helical and the tertiary structure depicts the typical left-handed super-helical twist of a two-stranded parallel alpha-helical coiled-coil. A buried salt bridge involving a histidine on the Max LZ and two glutamate residues on the c-Myc LZ is observed at the interface of the heterodimeric LZ. A buried H-bond between an asparagine side-chain and a backbone carbonyl is also observed. Moreover, evidence for e-g interhelical salt bridges is reported. These specific interactions give insights into the preferential heterodimerization process of the two LZs. The low stabilities of the Max homodimeric LZ and the c-Myc-Max heterodimeric LZ as well as the specific interactions observed are discussed with regard to regulation of transcription in this family of transcription factors. | ||
| - | |||
| - | ==Disease== | ||
| - | Known disease associated with this structure: Burkitt lymphoma OMIM:[[http://www.ncbi.nlm.nih.gov/entrez/dispomim.cgi?id=190080 190080]] | ||
==About this Structure== | ==About this Structure== | ||
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[[Category: Lavigne, P.]] | [[Category: Lavigne, P.]] | ||
[[Category: Sykes, B D.]] | [[Category: Sykes, B D.]] | ||
| - | [[Category: ACE]] | ||
| - | [[Category: NH2]] | ||
[[Category: 2d nmr]] | [[Category: 2d nmr]] | ||
[[Category: buried salt bridge]] | [[Category: buried salt bridge]] | ||
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[[Category: solution structure]] | [[Category: solution structure]] | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun Mar 30 18:35:52 2008'' |
Revision as of 15:36, 30 March 2008
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| Ligands: | , | ||||||
| Related: | 2A93
| ||||||
| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
NMR SOLUTION STRUCTURE OF THE C-MYC-MAX HETERODIMERIC LEUCINE ZIPPER, NMR, MINIMIZED AVERAGE STRUCTURE
Overview
The oncoprotein c-Myc (a member of the helix-loop-helix-leucine zipper (b-HLH-LZ) family of transcription factors) must heterodimerize with the b-HLH-LZ Max protein to bind DNA and activate transcription. It has been shown that the LZ domains of the c-Myc and Max proteins specifically form a heterodimeric LZ at 20 degreesC and neutral pH. This suggests that the LZ domains of the c-Myc and Max proteins are playing an important role in the heterodimerization of the corresponding gene products in vivo. Initially, to gain an insight into the energetics of heterodimerization, we studied the stability of N-terminal disulfide-linked versions of the c-Myc and Max homodimeric LZs and c-Myc-Max heterodimeric LZ by fitting the temperature-induced denaturation curves monitored by circular dichroism spectroscopy. The c-Myc LZ does not homodimerize (as previously reported) and the c-Myc-Max heterodimeric LZ is more stable than the Max homodimeric LZ at 20 degreesC and pH 7.0. In order to determine the critical interhelical interactions responsible for the molecular recognition between the c-Myc and Max LZs, the solution structure of the disulfide-linked c-Myc-Max heterodimeric LZ was solved by two-dimensional 1H-NMR techniques at 25 degreesC and pH 4.7. Both LZs are alpha-helical and the tertiary structure depicts the typical left-handed super-helical twist of a two-stranded parallel alpha-helical coiled-coil. A buried salt bridge involving a histidine on the Max LZ and two glutamate residues on the c-Myc LZ is observed at the interface of the heterodimeric LZ. A buried H-bond between an asparagine side-chain and a backbone carbonyl is also observed. Moreover, evidence for e-g interhelical salt bridges is reported. These specific interactions give insights into the preferential heterodimerization process of the two LZs. The low stabilities of the Max homodimeric LZ and the c-Myc-Max heterodimeric LZ as well as the specific interactions observed are discussed with regard to regulation of transcription in this family of transcription factors.
About this Structure
1A93 is a Protein complex structure of sequences from Homo sapiens and Mus musculus. Full crystallographic information is available from OCA.
Reference
Insights into the mechanism of heterodimerization from the 1H-NMR solution structure of the c-Myc-Max heterodimeric leucine zipper., Lavigne P, Crump MP, Gagne SM, Hodges RS, Kay CM, Sykes BD, J Mol Biol. 1998 Aug 7;281(1):165-81. PMID:9680483
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