Identification of proximal sites for unwound DNA substrate in Escherichia coli topoisomerase I with oxidative crosslinking.
FEBS Lett
; 591(1): 28-38, 2017 Jan.
Article
em En
| MEDLINE
| ID: mdl-27926785
ABSTRACT
Topoisomerases catalyze changes in DNA topology by directing the movement of DNA strands through consecutive cleavage-rejoining reactions of the DNA backbone. We describe the use of a phenylselenyl-modified thymidine incorporated into a specific position of a partially unwound DNA substrate in crosslinking studies of Escherichia coli topoisomerase I to gain new insights into its catalytic mechanism. Crosslinking of the phenylselenyl-modified thymidine to the topoisomerase protein was achieved by the addition of a mild oxidant. Following nuclease and trypsin digestion, lysine residues on topoisomerase I crosslinked to the modified thymidine were identified by mass spectrometry. The crosslinked sites may correspond to proximal sites for the unwound DNA strand as it interacts with enzyme in the different stages of the catalytic cycle.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
DNA Bacteriano
/
DNA Topoisomerases Tipo I
/
Reagentes de Ligações Cruzadas
Tipo de estudo:
Diagnostic_studies
Idioma:
En
Revista:
FEBS Lett
Ano de publicação:
2017
Tipo de documento:
Article
País de afiliação:
Estados Unidos