Tn4451 from Clostridium perfringens is a mobilizable transposon that encodes the functional Mob protein, TnpZ.
The 6.3 kb Clostridium perfringens transposon Tn4451 encodes a 50 kDa protein, TnpZ, which has amino acid sequence similarity to a group of plasmid mobilization and recombination proteins that comprise the Mob/Pre family. Members of this family interact with an upstream palindromic sequence called an RSA site, and an RSA-like sequence has been identified upstream of the tnpZ gene. In Escherichia coli, in the presence of a chromosomally integrated derivative of the broad-host-range IncP plasmid, RP4, TnpZ was able to promote plasmid mobilization in cis and was able to function in trans to enable the mobilization of a co-resident plasmid carrying an RSA site. It was also able to mediate the conjugative transfer of plasmids from E. coli to C. perfringens. Site-directed mutagenesis of two bases within the RSA site resulted in a significant reduction in mobilization frequency, demonstrating that the RSA site is required for efficient plasmid mobilization. TnpZ is the only Mob/Pre protein known to be associated with a transposable genetic element, and Tn4451 is the first mobilizable but non-self-transmissible transposon to be identified from a gram-positive bacterium.
Crellin
P K
PK
Department of Microbiology, Monash University, Clayton, Victoria, Australia.
Rood
J I
JI
D001426:Bacterial Proteins; D003016:Clostridium perfringens / Q000235:genetics*; D003227:Conjugation, Genetic; D004251:DNA Transposable Elements; D004587:Electrophoresis, Agar Gel; D004926:Escherichia coli / Q000235:genetics; D017353:Gene Deletion; D005798:Genes, Bacterial; D016297:Mutagenesis, Site-Directed; D010957:Plasmids; D011506:Proteins / Q000737:chemistry / Q000235:genetics* / Q000502:physiology; D015183:Restriction Mapping; D016415:Sequence Alignment
D001426:Bacterial Proteins; D004251:DNA Transposable Elements; D011506:Proteins; C111456:TNPZ protein, Clostridium perfringens