title: Asn(78) and His(81) form a destabilizing locus within the Max HLH-LZ homodimer.
abstract: The human Max protein lies at the center of the Myc/Max/Mad family of transcription factors. Its role at the center of this regulatory network is dependent on the helix-loop-helix leucine zipper (HLH-LZ) dimerization domain. The Max LZ contains three residues that deviate from the pattern of hydrophobic amino acids normally present at the interface of LZ dimers: Asn(78), His(81) and Asn(92). In contrast to interfacial Asn residues in other LZ proteins, we have shown that Asn(92) does not act to destabilize the homodimer. Here we describe thermal denaturation experiments performed on Asn(78) and His(81) mutants demonstrating that these residues are involved in actively destabilizing the Max homodimer.
authors.affiliation: Department of Biochemistry, University of Sydney, 2006, Sydney, NSW, Australia.
authors.forename: M C
authors.initials: MC
authors.lastname: Tchan
authors.forename: A S
authors.initials: AS
authors.lastname: Weiss
mesh_terms: D001216:Asparagine; D051778:Basic Helix-Loop-Helix Leucine Zipper Transcription Factors; D050976:Basic-Leucine Zipper Transcription Factors; D004268:DNA-Binding Proteins / Q000737:chemistry*; D018257:Helix-Loop-Helix Motifs; D006639:Histidine; D006358:Hot Temperature; D006801:Humans; D016350:Leucine Zippers; D011489:Protein Denaturation; D014157:Transcription Factors / Q000737:chemistry*
chemical_list: D051778:Basic Helix-Loop-Helix Leucine Zipper Transcription Factors; D050976:Basic-Leucine Zipper Transcription Factors; D004268:DNA-Binding Proteins; C499330:MAX protein, human; C067850:Myc associated factor X; D014157:Transcription Factors; D006639:Histidine; D001216:Asparagine