Abstract
The uptake of nickel in Escherichia coli and other microorganisms is transcriptionally regulated by the NikR repressor or its homologs. Here we report the structure of the high-affinity nickel-binding site in NikR and show that it responds dramatically to DNA binding. X-ray absorption spectroscopy reveals that nickel in the holo-NikR protein is bound in a novel four-coordinate planar site consisting of two histidines, one additional O- or N-donor ligand and one S-donor ligand. Site-directed mutation of His87, His89, Cys95 or Glu97 in NikR to alanine eliminates high-affinity nickel binding and abolishes DNA binding but maintains stable protein folding. An unanticipated feature of the NikR structure is that the nickel coordination responds to DNA binding. A six-coordinate nickel site composed of O- or N-donor ligands, but lacking cysteine, forms when NikR binds to operator DNA. Because nickel binding and DNA binding are mediated by different domains within NikR, a communication link between the two domains is implicated, consistent with the finding that the nickel-binding site in a fragment corresponding to the C-terminal domain of NikR is structurally distinct from that found in holo-NikR.
| Original language | English |
|---|---|
| Pages (from-to) | 126-130 |
| Number of pages | 5 |
| Journal | Nature Structural Biology |
| Volume | 10 |
| Issue number | 2 |
| DOIs | |
| Publication status | Published - Feb 1 2003 |
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ASJC Scopus subject areas
- Structural Biology
- Biochemistry
- Genetics
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Nickel coordination is regulated by the DNA-bound state of NikR. / Carrington, Paul E.; Chivers, Peter T.; Al-Mjeni, Faizah; Sauer, Robert T.; Maroney, Michael J.
In: Nature Structural Biology, Vol. 10, No. 2, 01.02.2003, p. 126-130.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Nickel coordination is regulated by the DNA-bound state of NikR
AU - Carrington, Paul E.
AU - Chivers, Peter T.
AU - Al-Mjeni, Faizah
AU - Sauer, Robert T.
AU - Maroney, Michael J.
PY - 2003/2/1
Y1 - 2003/2/1
N2 - The uptake of nickel in Escherichia coli and other microorganisms is transcriptionally regulated by the NikR repressor or its homologs. Here we report the structure of the high-affinity nickel-binding site in NikR and show that it responds dramatically to DNA binding. X-ray absorption spectroscopy reveals that nickel in the holo-NikR protein is bound in a novel four-coordinate planar site consisting of two histidines, one additional O- or N-donor ligand and one S-donor ligand. Site-directed mutation of His87, His89, Cys95 or Glu97 in NikR to alanine eliminates high-affinity nickel binding and abolishes DNA binding but maintains stable protein folding. An unanticipated feature of the NikR structure is that the nickel coordination responds to DNA binding. A six-coordinate nickel site composed of O- or N-donor ligands, but lacking cysteine, forms when NikR binds to operator DNA. Because nickel binding and DNA binding are mediated by different domains within NikR, a communication link between the two domains is implicated, consistent with the finding that the nickel-binding site in a fragment corresponding to the C-terminal domain of NikR is structurally distinct from that found in holo-NikR.
AB - The uptake of nickel in Escherichia coli and other microorganisms is transcriptionally regulated by the NikR repressor or its homologs. Here we report the structure of the high-affinity nickel-binding site in NikR and show that it responds dramatically to DNA binding. X-ray absorption spectroscopy reveals that nickel in the holo-NikR protein is bound in a novel four-coordinate planar site consisting of two histidines, one additional O- or N-donor ligand and one S-donor ligand. Site-directed mutation of His87, His89, Cys95 or Glu97 in NikR to alanine eliminates high-affinity nickel binding and abolishes DNA binding but maintains stable protein folding. An unanticipated feature of the NikR structure is that the nickel coordination responds to DNA binding. A six-coordinate nickel site composed of O- or N-donor ligands, but lacking cysteine, forms when NikR binds to operator DNA. Because nickel binding and DNA binding are mediated by different domains within NikR, a communication link between the two domains is implicated, consistent with the finding that the nickel-binding site in a fragment corresponding to the C-terminal domain of NikR is structurally distinct from that found in holo-NikR.
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U2 - 10.1038/nsb890
DO - 10.1038/nsb890
M3 - Article
VL - 10
SP - 126
EP - 130
JO - Nature Structural and Molecular Biology
JF - Nature Structural and Molecular Biology
SN - 1545-9993
IS - 2
ER -