This old version of Proteopedia is provided for student assignments while the new version is undergoing repairs. Content and edits done in this old version of Proteopedia after March 1, 2026 will eventually be lost when it is retired in about June of 2026.
Apply for new accounts at the new Proteopedia. Your logins will work in both the old and new versions.
1le8
From Proteopedia
|
Crystal Structure of the MATa1/MATalpha2-3A Heterodimer Bound to DNA Complex
Overview
Triply mutated MATalpha2 protein, alpha2-3A, in which all three major, groove-contacting residues are mutated to alanine, is defective in binding, DNA alone or in complex with Mcm1 yet binds with MATa1 with near wild-type, affinity and specificity. To gain insight into this unexpected behavior, we determined the crystal structure of the a1/alpha2-3A/DNA complex. The, structure shows that the triple mutation causes a collapse of the, alpha2-3A/DNA interface that results in a reorganized set of alpha2-3A/DNA, contacts, thereby enabling the mutant protein to recognize the wild-type, DNA sequence. Isothermal titration calorimetry measurements reveal that a, much more favorable entropic component stabilizes the a1/alpha2-3A/DNA, complex than the alpha2-3A/DNA complex. The combined structural and, thermodynamic studies provide an explanation of how partner proteins, influence the sequence specificity of a DNA binding protein.
About this Structure
1LE8 is a Protein complex structure of sequences from Saccharomyces cerevisiae. Full crystallographic information is available from OCA.
Reference
Structural and thermodynamic characterization of the DNA binding properties of a triple alanine mutant of MATalpha2., Ke A, Mathias JR, Vershon AK, Wolberger C, Structure. 2002 Jul;10(7):961-71. PMID:12121651
Page seeded by OCA on Tue Nov 20 20:30:33 2007
