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Crystal structure of Thermotoga maritima 0065, a member of the IclR transcriptional factor family.
Crystal structure of Thermotoga maritima 0065, a member of the IclR transcriptional factor family.
- Source :
-
The Journal of biological chemistry [J Biol Chem] 2002 May 24; Vol. 277 (21), pp. 19183-90. Date of Electronic Publication: 2002 Mar 04. - Publication Year :
- 2002
-
Abstract
- Members of the IclR family of transcription regulators modulate signal-dependent expression of genes involved in carbon metabolism in bacteria and archaea. The Thermotoga maritima TM0065 gene codes for a protein (TM-IclR) that is homologous to the IclR family. We have determined the crystal structure of TM-IclR at 2.2 A resolution using MAD phasing and synchrotron radiation. The protein is composed of two domains: the N-terminal DNA-binding domain contains the winged helix-turn-helix motif, and the C-terminal presumed regulatory domain is involved in binding signal molecule. In a proposed signal-binding site, a bound Zn(2+) ion was found. In the crystal, TM-IclR forms a dimer through interactions between DNA-binding domains. In the dimer, the DNA-binding domains are 2-fold related, but the dimer is asymmetric with respect to the orientation of signal-binding domains. Crystal packing analysis showed that TM-IclR dimers form a tetramer through interactions exclusively by signal-binding domains. A model is proposed for binding of IclR-like factors to DNA, and it suggests that signal-dependent transcription regulation is accomplished by affecting an oligomerization state of IclR and therefore its affinity for DNA target.
- Subjects :
- Amino Acid Sequence
Bacterial Proteins genetics
Base Sequence
Binding Sites
Cloning, Molecular
Crystallography, X-Ray
DNA, Bacterial metabolism
Models, Molecular
Molecular Sequence Data
Open Reading Frames
Repressor Proteins genetics
Sequence Homology, Amino Acid
Bacterial Proteins chemistry
Escherichia coli Proteins
Repressor Proteins chemistry
Thermotoga maritima metabolism
Transcription Factors
Subjects
Details
- Language :
- English
- ISSN :
- 0021-9258
- Volume :
- 277
- Issue :
- 21
- Database :
- MEDLINE
- Journal :
- The Journal of biological chemistry
- Publication Type :
- Academic Journal
- Accession number :
- 11877432
- Full Text :
- https://doi.org/10.1074/jbc.M112171200