Characterization of DRA0282 from Deinococcus radiodurans for its role in bacterial resistance to DNA damage.
Microbiology (Reading)
; 157(Pt 8): 2196-2205, 2011 Aug.
Article
em En
| MEDLINE
| ID: mdl-21511764
ABSTRACT
DRA0282, a hypothetical protein, was found in a pool of nucleotide-binding proteins in Deinococcus radiodurans cells recovering from gamma radiation stress. This pool exhibited an unusual inhibition of nuclease activity by ATP. The N terminus of DRA0282 showed similarity to human Ku80 homologues, while the C terminus showed no similarities to known proteins. The recombinant protein required Mn(2+) for its interaction with DNA and protected dsDNA from exonuclease III degradation. The binding of the protein to supercoiled DNA with a K(d) of ~2.93 nM was nearly 20-fold stronger than its binding to ssDNA and nearly 67-fold stronger than its binding to linear dsDNA. Escherichia coli cells expressing DRA0282 showed a RecA-dependent enhancement of UV and gamma radiation tolerance. The ΔdrA0282 mutant of D. radiodurans showed a dose-dependent response to gamma radiation. At 14 kGy, the ΔdrA0282 mutant showed nearly 10-fold less survival, while at this dose both pprAâââcatΔdrA0282 and pprAâââcat mutants were nearly 100-fold more sensitive than the wild-type. These results suggested that DRA0282 is a DNA-binding protein with a preference for superhelical DNA, and that it plays a role in bacterial resistance to DNA damage through a pathway in which PprA perhaps plays a dominant role in D. radiodurans.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Proteínas de Bactérias
/
Dano ao DNA
/
Deinococcus
/
Proteínas de Ligação a DNA
Idioma:
En
Revista:
Microbiology (Reading)
Assunto da revista:
MICROBIOLOGIA
Ano de publicação:
2011
Tipo de documento:
Article
País de afiliação:
Índia