Saha, R. ; Banik, U. ; Bandopadhyay, S. ; Mandal, N. C. ; Bhattacharyya, B. ; Roy, S. (1992) An operator-induced conformational change in the C-terminal domain of the λ repressor Journal of Biological Chemistry, 267 (9). pp. 5862-5867. ISSN 0021-9258
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Official URL: http://www.jbc.org/content/267/9/5862.abstract?sid...
Abstract
4,4'-bis(1-anilino-8-naphthalenesulfonic acid (Bis-ANS), an environment-sensitive fluorescent probe for hydrophobic region of proteins, binds specifically to the C-terminal domain of λ repressor. The binding is characterized by positive cooperativity, the magnitude of which is dependent on protein concentration in the concentration range where dimeric repressor aggregates to a tetramer. In this range, positive cooperativity becomes more pronounced at higher protein concentrations. This suggests a preferential binding of Bis-ANS to the dimeric form of the repressor. Binding of single operator OR1 to the N-terminal domain of the repressor causes enhancement of fluorescence of the C-terminal domain bound Bis-ANS. The binding of single operator OR1 also leads to quenching of fluorescence of tryptophan residues, all of which are located in the hinge or the C-terminal domain. Thus two different fluorescent probes indicate an operator-induced conformational change which affects the C-terminal domain. The significance of this conformational change with respect to the function of λ repressor has been discussed.
Item Type: | Article |
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Source: | Copyright of this article belongs to American Society for Biochemistry and Molecular Biology. |
ID Code: | 26143 |
Deposited On: | 06 Dec 2010 13:01 |
Last Modified: | 17 May 2016 09:29 |
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