TY - JOUR
T1 - Crystal structure of LacI member, PurR, bound to DNA
T2 - Minor groove binding by α helices
AU - Schumacher, Maria A.
AU - Choi, Kang Yell
AU - Zalkin, Howard
AU - Brennan, Richard G.
PY - 1994
Y1 - 1994
N2 - The three-dimensional structure of a ternary complex of the purine repressor, PurR, bound to both its compressor, hypoxanthine, and the 16-base pair purF operator site has been solved at 2.7 Å resolution by x-ray crystallography. The bipartite structure of PurR consists of an amino-terminal DNA-binding domain and a larger carboxyl-terminal corepressor binding and dimerization domain that is similar to that of the bacterial periplasmic binding proteins. The DNA-binding domain contains a helix-turn-helix motif that makes base-specific contacts in the major groove of the DNA. Base contacts are also made by residues of symmetry-related α helices, the "hinge" helices, which bind deeply in the minor groove. Critical to hinge helix-minor groove binding is the intercalation of the side chains of Leu54 and its symmetry-related mate, Leu54′, into the central CpG-base pair step. These residues thereby act as "leucine levers" to pry open the minor groove and kink the purF operator by 45 degrees.
AB - The three-dimensional structure of a ternary complex of the purine repressor, PurR, bound to both its compressor, hypoxanthine, and the 16-base pair purF operator site has been solved at 2.7 Å resolution by x-ray crystallography. The bipartite structure of PurR consists of an amino-terminal DNA-binding domain and a larger carboxyl-terminal corepressor binding and dimerization domain that is similar to that of the bacterial periplasmic binding proteins. The DNA-binding domain contains a helix-turn-helix motif that makes base-specific contacts in the major groove of the DNA. Base contacts are also made by residues of symmetry-related α helices, the "hinge" helices, which bind deeply in the minor groove. Critical to hinge helix-minor groove binding is the intercalation of the side chains of Leu54 and its symmetry-related mate, Leu54′, into the central CpG-base pair step. These residues thereby act as "leucine levers" to pry open the minor groove and kink the purF operator by 45 degrees.
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U2 - 10.1126/science.7973627
DO - 10.1126/science.7973627
M3 - Article
C2 - 7973627
AN - SCOPUS:0028173030
VL - 266
SP - 763
EP - 770
JO - Science
JF - Science
SN - 0036-8075
IS - 5186
ER -