Difference between revisions of "Part:BBa K512002"

Revision as of 02:55, 29 September 2011

Usage and Biology

Studies have shown that Escherichia coli bacteria have a system that provides immunity against viral infections and plasmid conjugation in the natural world. This recently discovered system, also known as the CRISPR/Cas system, is made of eight cas (CRISPR-associated) genes and an array of repeats and spacers known as CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats). The repeats are repeating DNA sequences of approximately thirty nucleotides that are separated by unique genetic elements, spacers. The sequences of these spacers are generally derived from foreign virus DNA or plasmids. The CRISPR array expands when the bacteria collects a new spacer in a process known as CRISPR adaptation. The bacteria only confers resistance to the virus or plasmid when its CRISPR repertoire contains a spacer that matches the DNA sequence of the invading DNA. Although parts of the pathway for CRISPR adaptation and CRISPR interference are being studied, many mechanisms such as spacer integration into the CRISPR array as well as the degradation signaling pathway for CRISPR-targeted DNA remain to be discovered.

Proof of operation:

In the chart above, BL-D1 are the cells without IPTG, BL-D2 are with IPTG; and for BL-D3, we add IPTG 2 hours later. IPTG can induce CRISPR to target the plasmid. As we can see from the chart, with cas3 and CRISPR, the growth rate and optical density are decreased significantly compare to the cells without IPTG.

For complete and other results, please check the link [http://2011.igem.org/Team:USC/Project]

Sequence and Features

Assembly Compatibility:

10
INCOMPATIBLE WITH RFC[10]
Illegal EcoRI site found at 222
12
INCOMPATIBLE WITH RFC[12]
Illegal EcoRI site found at 222
21
INCOMPATIBLE WITH RFC[21]
Illegal EcoRI site found at 222
Illegal BamHI site found at 344
23
INCOMPATIBLE WITH RFC[23]
Illegal EcoRI site found at 222
25
INCOMPATIBLE WITH RFC[25]
Illegal EcoRI site found at 222
Illegal AgeI site found at 265
1000
COMPATIBLE WITH RFC[1000]

@@ Line 1: / Line 1: @@
-__NOTOC__
-<partinfo>BBa_K512002 short</partinfo>
-CRISPR
-<!-- Add more about the biology of this part here
 ===Usage and Biology===
-Bacteria protect their genome and remove foreign DNA elements through the use of the clustered, regularly interspaced short palindromic repeat (CRIPSR) system. Recently discovered, this defense mechanism can protect microorganisms against bacteriaphages. The CRISPR system comprises a transcribed locus of repeats and spacers that is activated and made functional via a family of CAS proteins. The CRISPR repeats are short DNA sequences that are almost identical in size and sequence. Between a pair of repeats is a spacer, which if complementary to a DNA element of the invading bacteriaphage, facilitates the destruction of that sequence from the bacterial cell. As such, the CRISPR/CAS system is a primitive biological defense mechanism, similar in many ways to the process of adaptive immunity in eukaryotic immune systems. Plasmids, which are commonly used in molecular biology are also the source of horizontal gene transfer in the wild and facilitate the spread of antibiotic resistant genes among microorganisms. These plasmids can contain unique DNA sequences that could be targeted by the CRISPR/CAS system.
+Studies have shown that Escherichia coli bacteria have a system that provides immunity against viral infections and plasmid conjugation in the natural world. This recently discovered system, also known as the CRISPR/Cas system, is made of eight cas (CRISPR-associated) genes and an array of repeats and spacers known as CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats). The repeats are repeating DNA sequences of approximately thirty nucleotides that are separated by unique genetic elements, spacers. The sequences of these spacers are generally derived from foreign virus DNA or plasmids. The CRISPR array expands when the bacteria collects a new spacer in a process known as CRISPR adaptation. The bacteria only confers resistance to the virus or plasmid when its CRISPR repertoire contains a spacer that matches the DNA sequence of the invading DNA. Although parts of the pathway for CRISPR adaptation and CRISPR interference are being studied, many mechanisms such as spacer integration into the CRISPR array as well as the degradation signaling pathway for CRISPR-targeted DNA remain to be discovered.
 Proof of operation: