Structure of the binuclear metal-binding site in the GAL4 transcription factor

Journal Article · Tue Nov 26 00:00:00 EST 1991 · Biochemistry; (United States)

DOI:https://doi.org/10.1021/bi00111a015· OSTI ID:5488383

Gardner, K H; Pan, Tao; Narula, S; Rivera, E; Coleman, J E ^[1]

---

1. Yale Univ., New Haven, CT (United States)

The GAL4 transcription factor from yeast contains within its N-terminal DNA-binding domain an amino acid sequence containing six cysteine residues, C11-X{sub 2}-C14-X{sub 6}-C21-X{sub 6}-C28-X{sub 2}-C31-X{sub 6}-C38. The six Cys residues will form a binuclear metal cluster with either Zn(II) or Cd(II) in which two of the -S{sup {minus}} donors are bridging ligands between the two metal ions. Binding of Zn(II) or Cd(II) to the GAL4 DNA-binding domain is essential to induce the conformation of GAL4 required for the protein to recognize the specific DNA sequence, UAS{sub G}, to which GAL4 binds. Evidence for the presence of the binuclear cluster has come from {sup 113}Cd NMR and 2D {sup 1}H-{sup 113}Cd heteronuclear NMR studies of the cloned DNA-binding domain of GAL4 consisting of the N-terminal 62 residues, GAL4(62*). A metal-ligand structure derived from the {sup 1}H-{sup 113}Cd heteronuclear NMR as well as the polypeptide backbone connectivity around the cluster as determined from short-range {sup 1}H-{sup 1}H NOE's is presented. The metal ions also determine the major folding of GAL4(62*), since the chemical shift dispersion in the entire NH-{alpha}CH fingerprint region of the {sup 1}H-{sup 1}H COSY spectrum collapses on removal of the metal ion. These NOE's show significant differences in magnitude relative to the {alpha}N(i,i+1) NOE's for the same residues between the Cd{sub 2} and Zn{sub 2} proteins as well as between the Zn{sub 2} and Zn{sub 1} proteins. Thus both the species of metal ion (Zn(II) or Cd(II)) and the number of metal ions bound determine the conformation of the peptide backbone.

• OSTI ID: 5488383
• Journal Information: Biochemistry; (United States), Vol. 30:47; ISSN 0006-2960
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
METALLOPROTEINS
NUCLEAR MAGNETIC RESONANCE
TRANSCRIPTION FACTORS
MOLECULAR STRUCTURE
CADMIUM 113
OVERHAUSER EFFECT
PROTONS
YEASTS
BARYONS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
CADMIUM ISOTOPES
ELEMENTARY PARTICLES
EUMYCOTA
EVEN-ODD NUCLEI
FERMIONS
FUNGI
HADRONS
INTERMEDIATE MASS NUCLEI
INTERNAL CONVERSION RADIOISOTOPES
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
MAGNETIC RESONANCE
MICROORGANISMS
NUCLEI
NUCLEONS
NUCLEOPROTEINS
ORGANIC COMPOUNDS
PLANTS
PROTEINS
RADIOISOTOPES
RESONANCE
STABLE ISOTOPES
YEARS LIVING RADIOISOTOPES
550201* - Biochemistry- Tracer Techniques