The functional and structural-dynamical properties of the Lys681Ala mutation in the human topoisomerase IB linker domain have been investigated by catalytic assays and molecular dynamics simulation. The mutant is characterized by a comparable cleavage and a strongly reduced religation rate when compared to the wild type protein. The mutant also displays perturbed linker dynamics, as shown by analysis of the principal components of the motion, and a reduced electrostatic interaction with DNA. Inspection of the inter atomic distances in proximity of the active site shows that in the mutant the distance between the amino group of Lys532 side chain and the 5' OH of the scissile phosphate is longer than the wild type enzyme, providing an atomic explanation for the reduced religation rate of the mutant. Taken together these results indicate the existence of a long range communication between the linker domain and the active site region and points out the crucial role of the linker in the modulation of the catalytic activity.

Fiorani, P., Tesauro, C., Mancini, G., Chillemi, G., D'Annessa, I., Graziani, G., et al. (2009). Evidence of the crucial role of the linker domain on the catalytic activity of human topoisomerase I by experimental and simulative characterization of the Lys681Ala mutant. NUCLEIC ACIDS RESEARCH, 37(20), 6849-6858 [10.1093/nar/gkp669].

Evidence of the crucial role of the linker domain on the catalytic activity of human topoisomerase I by experimental and simulative characterization of the Lys681Ala mutant

GRAZIANI, GRAZIA;TENTORI, LUCIO;MUZI, ALESSIA;DESIDERI, ALESSANDRO
2009-11-01

Abstract

The functional and structural-dynamical properties of the Lys681Ala mutation in the human topoisomerase IB linker domain have been investigated by catalytic assays and molecular dynamics simulation. The mutant is characterized by a comparable cleavage and a strongly reduced religation rate when compared to the wild type protein. The mutant also displays perturbed linker dynamics, as shown by analysis of the principal components of the motion, and a reduced electrostatic interaction with DNA. Inspection of the inter atomic distances in proximity of the active site shows that in the mutant the distance between the amino group of Lys532 side chain and the 5' OH of the scissile phosphate is longer than the wild type enzyme, providing an atomic explanation for the reduced religation rate of the mutant. Taken together these results indicate the existence of a long range communication between the linker domain and the active site region and points out the crucial role of the linker in the modulation of the catalytic activity.
nov-2009
Pubblicato
Rilevanza internazionale
Articolo
Sì, ma tipo non specificato
Settore BIO/14 - FARMACOLOGIA
English
Con Impact Factor ISI
Static Electricity; Base Sequence; Alanine; DNA Topoisomerases, Type I; Humans; Point Mutation; Molecular Sequence Data; Catalytic Domain; Lysine; Protein Structure, Tertiary; Mutation; Catalysis
Fiorani, P., Tesauro, C., Mancini, G., Chillemi, G., D'Annessa, I., Graziani, G., et al. (2009). Evidence of the crucial role of the linker domain on the catalytic activity of human topoisomerase I by experimental and simulative characterization of the Lys681Ala mutant. NUCLEIC ACIDS RESEARCH, 37(20), 6849-6858 [10.1093/nar/gkp669].
Fiorani, P; Tesauro, C; Mancini, G; Chillemi, G; D'Annessa, I; Graziani, G; Tentori, L; Muzi, A; Desideri, A
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/2108/41513
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