IncI1 plasmid R64 encodes the ArsR protein that alleviates type I restriction

FEBS Letters

Zavilgelsky, Gennadii B²  Tchurikov, Nickolai A¹  Rastorguev, Sergei M² 

[1] Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Vavilov str. 32, Moscow 117984, Russia;State Scientific Centre of Russian Federation GNIIGENETIKA, 1th Dorozhnii pr. 1, Box 825, Moscow 113545, Russia

关键词: Self-transmissible plasmid;    Antirestriction;    ard gene;    ars operon;    `Antirestriction motif';   

DOI  :  10.1016/S0014-5793(98)00285-3

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The host-controlled EcoK restriction of unmodified phage λ was five-fold alleviated in the wild-type Escherichia coli strain K12 carrying the R64 plasmid of the incompatibility group I1. The relevant gene was mapped between the origin of vegetative replication (rep, oriV) and the tet ^r gene about 60 kbp downstream from the origin of transfer, oriT. We cloned this gene inside the 613 bp long EcoRI-PstI fragment and sequenced it. Only one 351 bp long open reading frame (ORF) starting at 124 bp from the beginning of the insert was found in the sequence. Computer search in the current databases revealed that the putative protein is identical to the ArsR protein specified by the IncFI plasmid R773. ArsR is a repressor of the arsenical resistance (ars) operon, arsRDABC. There are no arsABC genes in the R64 plasmid since plasmid R64- (or pSR8)-mediated resistance of E. coli K12 cells to the arsenicals arsenate and arsenite was not detected. The gene arsR and the antirestriction genes ard (ardA and ardB) are non-homologous. However, comparison of the deduced amino acid sequence of ArsR with the ArdA and ArdB sequences revealed only one small region of similarity, a 9 amino acid motif found in different antirestriction proteins that is hypothesized to be an interaction site for antirestriction proteins with restriction endonucleases.

【 授权许可】

Unknown