NikR repressor: High-affinity nickel binding to the C-terminal domain regulates binding to operator DNA
被引:95
作者:
Chivers, PT
论文数: 0引用数: 0
h-index: 0
机构:
MIT, Dept Biol, Cambridge, MA 02138 USAMIT, Dept Biol, Cambridge, MA 02138 USA
Chivers, PT
[1
]
Sauer, RT
论文数: 0引用数: 0
h-index: 0
机构:
MIT, Dept Biol, Cambridge, MA 02138 USAMIT, Dept Biol, Cambridge, MA 02138 USA
Sauer, RT
[1
]
机构:
[1] MIT, Dept Biol, Cambridge, MA 02138 USA
来源:
CHEMISTRY & BIOLOGY
|
2002年
/
9卷
/
10期
关键词:
D O I:
10.1016/S1074-5521(02)00241-7
中图分类号:
Q5 [生物化学];
Q7 [分子生物学];
学科分类号:
071010 ;
081704 ;
摘要:
E coli NikR repressor binds operator DNA in a nickel-dependent fashion. The pM affinity of NikR for nickel is mediated by its C-terminal 86 residues. Nickel binding induced additional secondary structure, decreased the compactness, and increased the stability of NikR. Tetramer formation by the C-terminal domain and intact NikR did not require nickel. High-affinity nickel binding decreased the NikR concentration needed to half maximally protect operator DNA from undetectable levels to 30 nM. The intracellular concentration of NikR in E. coli is high enough that saturation of the high-affinity nickel sites should lead to substantial occupancy of the nik operator. Nickel binding to a set of low-affinity NikR sites resulted in an additional large increase in operator affinity and substantially increased the size of the NikR footprint on the operator.