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Purification and characterization of repressor of temperate S. aureus phage phi11.
- Source :
-
Journal of biochemistry and molecular biology [J Biochem Mol Biol] 2007 Sep 30; Vol. 40 (5), pp. 740-8. - Publication Year :
- 2007
-
Abstract
- To gain insight into the structure and function of repressor proteins of bacteriophages of gram-positive bacteria, repressor of temperate Staphylococcus aureus phage phi11 was undertaken as a model system here and purified as an N-terminal histidine-tagged variant (His-CI) by affinity chromatography. A approximately 19 kDa protein copurified with intact His-CI (approximately 30 kDa) at low level was resulted most possibly due to partial cleavage at its Ala-Gly site. At approximately 10 nM and higher concentrations, His-CI forms significant amount of dimers in solution. There are two repressor binding sites in phi11 cI-cro intergenic region and binding to two sites occurs possibly by a cooperative manner. Two sites dissected by HincII digestion were designated operators O(L) and O(R), respectively. Equilibrium binding studies indicate that His-CI binds to O(R) with a little more strongly than O(L) and binding species is probably dimeric in nature. Interestingly His-CI binding affinity reduces drastically at elevated temperatures (32-42 degrees C). Both O(L) and O(R) harbor a nearly identical inverted repeat and studies show that phi11 repressor binds to each repeat efficiently. Additional analyses indicate that phi11 repressor, like lambda repressor, harbors an N-terminal domain and a C-terminal domain which are separated by a hinge region. Secondary structure of phi11 CI even nearly resembles to that of lambda, phage repressor though they differ at sequence level. The putative N-terminal HTH (helix-turn-helix) motif of phi11 repressor belongs to the HTH -XRE-family of proteins and shows significant identity to the HTH motifs of some proteins of evolutionary distant organisms but not to HTH motifs of most S. aureus phage repressors.
- Subjects :
- Amino Acid Sequence
Bacteriophages genetics
Base Sequence
Chromatography, Affinity
Dimerization
Electrophoretic Mobility Shift Assay
Molecular Sequence Data
Operator Regions, Genetic genetics
Phylogeny
Protein Binding
Repressor Proteins chemistry
Repressor Proteins genetics
Viral Proteins genetics
Viral Proteins isolation & purification
Bacteriophages metabolism
Repressor Proteins metabolism
Staphylococcus aureus virology
Viral Proteins metabolism
Subjects
Details
- Language :
- English
- ISSN :
- 1225-8687
- Volume :
- 40
- Issue :
- 5
- Database :
- MEDLINE
- Journal :
- Journal of biochemistry and molecular biology
- Publication Type :
- Academic Journal
- Accession number :
- 17927908
- Full Text :
- https://doi.org/10.5483/bmbrep.2007.40.5.740