Difference between revisions of "Resources/Plant Synthetic Biology/PhytoBricks"
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<h3>Making Multi-Gene Constructs</h3> | <h3>Making Multi-Gene Constructs</h3> | ||
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| − | + | Four Golden Braid (GB2.0) plasmid backbones (a href="http://parts.igem.org/Part:BBa_P10501">BBa_P10501</a>, <a href="http://parts.igem.org/Part:BBa_P10503">BBa_P10503</a>, <a href="http://parts.igem.org/Part:BBa_P10505">BBa_P10505</a>, and <a href="http://parts.igem.org/Part:BBa_P10507">BBa_P10507</a>) have been included as part of the 2016 Distribution Kit to provide teams with an easy-to-use system for assembling multi-gene constructs with the PhytoBricks provided in the 2016 Distribution Kit (see below). These plasmids contain all of the features necessary for assembly of PhytoBricks and for Agrobacterium-mediated delivery to plant cells. Below, we describe how to use these vectors for building multi-gene constructs. | |
<br><br> | <br><br> | ||
PhytoBricks are assembled into complete trancriptional units that go from the promoter through the terminator (as shown in <b><i>Figure 2</b></i>) in GB2.0 level α acceptors. Two level α constructs can be combined in a level Ω destination vector using <i>BsmBI</i> (<b><i>Figure 3</b></i>). Inversely, two level Ω constructs can be assembled in a level α destination vector with <i>BsaI</i>. Successive iterations are used to create large multigene constructs, with each new construct able to be reused in new assemblies. Detailed assembly protocols for these plasmids are available at https://gbcloning.upv.es </a></p><br><br> | PhytoBricks are assembled into complete trancriptional units that go from the promoter through the terminator (as shown in <b><i>Figure 2</b></i>) in GB2.0 level α acceptors. Two level α constructs can be combined in a level Ω destination vector using <i>BsmBI</i> (<b><i>Figure 3</b></i>). Inversely, two level Ω constructs can be assembled in a level α destination vector with <i>BsaI</i>. Successive iterations are used to create large multigene constructs, with each new construct able to be reused in new assemblies. Detailed assembly protocols for these plasmids are available at https://gbcloning.upv.es </a></p><br><br> | ||
Revision as of 19:08, 10 June 2016
What are PhytoBricks?
Standard parts for plants are known as PhytoBricks. These parts are based on the Golden Gate Modular Cloning Type IIS assembly method and can be expanded to include other chassis, including bacteria and yeast. This year, teams can submit PhytoBrick samples for any chassis to us if (1) they follow the fusion site rules we provide below and (2) submit the parts using our Universal Acceptor vector (BBa_P10500), which is pSB1C3 with a Type IIS cloning site inserted between the BioBrick prefix and suffix.
PhytoBricks are sequences flanked by a convergent pair of BsaI recognition sequences (Figure 1). BsaI is a Type IIS restriction endonuclease that cuts outside of its recognition site. PhytoBricks are housed in a Universal Acceptor Backbone derived from the pSB1C3 BioBrick backbone and therefore contains a gene to confer resistance to chloramphenicol in bacteria (Figure 1). PhytoBrick parts do NOT include the flanking BsaI recognition sites. The PhytoBrick part sequence begins with the first letter (A, C, T, G) of the four base pair overhang created by digestion with BsaI and ends with the last letter of the other overhang (Figure 1).
Figure 1. Phytobricks are housed in a chloramphenicol resistant plasmid backbone - a derivative of pSB1C3 - flanked by convergent pair of BsaI sites. The overhangs created by digestion with BsaI must conform to the Common Syntax for plants - see below.
Illegal Restriction Sites
PhytoBricks should be free from the BsaI recognition, GGTCTC. This sequence is considered illegal. Additionally, it is recommended that parts are also free of BsmBI (Esp3I) and BpiI (BbsI) recognition sites (see multigene assembly, below). Phytobricks do NOT need to be free of the BBF RFC 10 restriction enzymes (EcoRI, XbaI, SpeI, PstI).
Fusion Sites
Specific four base pair overhangs, or fusion sites, have been defined for PhytoBricks. Eukaryotic genetic syntax has been broken into ten functional elements, therefore defining twelve overhangs (Figure 2). This is known as the Common Genetic Syntax. A PhytoBrick may a contain one of these elements or multiple adjacent elements (Figure 2). Correct use of these overhangs will ensure that PhytoBricks can be assembled into complete transcription units in a one-pot, one-step reaction.
Figure 2. The common syntax defines twelve fusion sites that divide eukaryotic genes into ten basic functional units. Parts may comprise one or more adjacent units but must be free from internal BsaI recognition sequences. To be compatible with the Golden Gate Modular Cloning (MoClo) and GoldenBraid2.0 (GB2.0) assembly toolkits they must also be free from BpiI and BsmBI recognition sequences. Parts are housed in plasmid backbones flanked by convergent BsaI recognition sites. All transcriptional units begin GGAG and end CGCT. Parts can be assembled into complete transcriptional units in a single digestion–ligation reaction providing compatible overhangs are produced on digestion and the acceptor plasmid has divergent BsaI recognition site and a unique bacterial selection cassette.
Assembling Phytobricks into Transcriptional Units and Multigene Constructs
Use of PhytoBricks does not limit users to any specific plasmid toolkit for assembling complete genes or multi gene constructs. The requirements for the acceptor plasmid into which you assemble PhytoBricks are that:
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a) it contains a gene for resistance to an antibiotic other than chloramphenicol
b) it contains two divergent recognition sites of BsaI that make GGAG and CGCT overhangs when digested.
Compliance with these restraints will allow multiple parts to be assembled in a one-pot, one-step reaction.
Depending on what you plan to do with your transcriptional unit your plasmid might need additional features. If you plan to use Agrobacterium-mediated delivery to plant tissue then you will need to use a backbone with the appropriate features for this.
Read the Plants and iGEM page for more information about Agrobacterium-mediated transfection and transformation.
Making Multi-Gene Constructs
Four Golden Braid (GB2.0) plasmid backbones (a href="http://parts.igem.org/Part:BBa_P10501">BBa_P10501, BBa_P10503, BBa_P10505, and BBa_P10507) have been included as part of the 2016 Distribution Kit to provide teams with an easy-to-use system for assembling multi-gene constructs with the PhytoBricks provided in the 2016 Distribution Kit (see below). These plasmids contain all of the features necessary for assembly of PhytoBricks and for Agrobacterium-mediated delivery to plant cells. Below, we describe how to use these vectors for building multi-gene constructs.
PhytoBricks are assembled into complete trancriptional units that go from the promoter through the terminator (as shown in Figure 2) in GB2.0 level α acceptors. Two level α constructs can be combined in a level Ω destination vector using BsmBI (Figure 3). Inversely, two level Ω constructs can be assembled in a level α destination vector with BsaI. Successive iterations are used to create large multigene constructs, with each new construct able to be reused in new assemblies. Detailed assembly protocols for these plasmids are available at https://gbcloning.upv.es
Figure 3. Schematic for assembly of multi gene constructs from PhytoBricks using the GoldenBraid α and Ω plasmid system.
PhytoBricks in the Registry
The Registry contains a number of plant PhytoBricks and assembly vectors for teams to use this year. These have been included in the 2016 Distribution Kit and are located in Kit Plate 6 and are listed below (each links to its Registry page).
PhytoBricks
BBa_P10000
BBa_P10001
BBa_P10002
BBa_P10003
BBa_P10004
BBa_P10100
BBa_P10101
BBa_P10200
BBa_P10201
BBa_P10202
PhytoBricks
BBa_P10300
BBa_P10301
BBa_P10302
BBa_P10303
BBa_P10304
BBa_P10305
BBa_P10306
BBa_P10400
BBa_P10401
BBa_P10402
Vectors
BBa_P10500 (Universal Acceptor)BBa_P10501 (GB2.0 α-1)
BBa_P10502 (GB2.0 α-1R)*
BBa_P10503 (GB2.0 α-2)
BBa_P10504 (GB2.0 α-2R)*
BBa_P10505 (GB2.0 Ω-1)
BBa_P10506 (GB2.0 Ω-1R)*
BBa_P10507 (GB2.0 Ω-2)
BBa_P10508 (GB2.0 Ω-2R)*
* Not included in Kit Plate 6. Available through a Part Request
How to make New Phytobricks
An information sheet on how to make new PhytoBricks, including detailed information on primer design can be downloaded HERE. Only one version of the universal acceptor (called pUPD2 in the document) is included in the 2016 iGEM Plasmid Distribution kit. This vector, BBa_P10500, has lacZ flanked by BsmBI and BsaI in the cloning site in pSB1C3.
