The Applications of Transposomics™ Are Limited
Only by Our Imagination
The field of Transposomics™ exploits the ability of certain transposase
enzymes to catalyze the random "hop" or insertion of an "artificial" transposon
into any other DNA during a brief in vitro or in vivo transposition
reaction. The transposon can be any DNA that has a transposase
recognition sequence on each end (e.g., Figure 1). An artificial transposon
doesn't encode a transposase, but can encode selectable markers, priming
sites, origins of replication, RNA polymerase promoters, or other genetic
elements or control sequences.
| ||Figure 1. An EZ-Tn5™ Transposon. An EZ-Tn5 Transposon
can be any DNA sequence that is between properly-oriented 19-bp inverted
repeat Mosaic End (ME) sequences that are specifically and uniquely
recognized by EZ-Tn5™ Transposase. The EZ-Tn5 System is based
on the hyperactive Tn5 in vitro transposition system
described by IY Goryshin & WS Reznikoff1. This system
retains the insertion characteristics of Tn5–the most random
transposon system known–but has a transposition frequency 1000-fold
higher than wild-type Tn5. Epicentre also has a HyperMu™ In
Vitro Transposition System that is 50-100 times more active than
other MuA Transposase Systems. |
In DNA Sequencing, we presented a comparison of the properties of transposon
systems and our system for naming transposons. We also described how
EZ-Tn5™ or HyperMu™ in vitro transposition systems
can be used to simplify and speed up DNA sequencing. In following categories,
we discuss how In Vivo Transposomics is revolutionizing microbial
genetics by providing tools for studying organisms for which genetic
tools were not previously available, and methods and new transposon tools
for protein engineering and mapping of protein domains or epitopes.
Even the methods and products covered in other categories do not cover
all of the applications or indicate the full power of Transposomics,
nor could we hope to do so in this catalog. Our goal in the present category
is to provide a few examples of additional applications and transposon
tools for In Vitro Transposomics. The rest is up to your imagination.
Examples of In Vitro Transposomics Applications
Although the above examples are given for EZ-Tn5 Systems, researchers
can develop similar transposons for use in vitro with Epicentre's
HyperMu™ MuA Transposase. The first in vitro transposition
system was developed by Dr. Kiyoshi Mizuuchi using the well-characterized
temperate bacteriophage Mu2,3. However, until the introduction
of Epicentre's HyperMu™ MuA Transposase, Mu-based in vitro transposition
systems have not had transposition efficiencies that approached those
of Epicentre's EZ-Tn5 Insertion Systems. High transposition efficiencies
are critical for some applications. Epicentre's HyperMu MuA Transposase
is a hyperactive enzyme that retains the random insertion characteristics
of wild-type MuA transposase4 but is at least 50 times more
active in vitro than the MuA transposase available from other
suppliers. Also, since HyperMu MuA Transposase recognizes the same R1
and R2 end sequences as wild-type MuA Transposase5 , it can
be used with HyperMu transposons as well as other artificial Mu transposons.
Strategies That Use Both EZ-Tn5 and HyperMu Transposon Systems
EZ-Tn5 and HyperMu Transposases do not recognize the same end sequences
for transposition. Therefore, both systems can be used in strategies
in which it is desirable to use more than one transposon system.
- IY Goryshin & WS Reznikoff (1998) J Biol Chem 273,
- Mizuuchi, K (1983) Cell 35, 785.
- Chaconas, G & Harshey, RM (2002) in: Mobile DNA II, ASM
Press, Washington, D.C.
- Butterfield, YSN et al.(2002) Nucleic Acids Res. 30,
- Savilahti, H et al. (1995) EMBO J. 14, 4893.
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