Difference between revisions of "Part:BBa K567015"

Revision as of 02:28, 29 October 2011

PT7-metGN

T7 promoter-metG(truncated). This biobrick is constructed by putting the truncated metG (MetRS) under the control of T7 promoter and lac operator. We have cloned metG from E.coli and the tRNA recognition domain of MetRS is truncated. KanR gene with start codon substituted for CGA is used to testify the function of mutated metG. When this biobrick and metY-CGA (BBa_K567016) are co-transformed into the cell, the cells can survive on the LB Kana plate.

Construction of BBa_K567015

Rational design of MetRS: we have obtained a truncated MetRS without anticodon recognition domain. The structure of the truncated protein is shown below. This modified MetRS can charge tRNA^Met without recognizing its anticodon.

Fig. This design is based on the crystal structure of methionyl-tRNA synthetase complex with tRNA (PDB ID：2CSX). We have superimposed the crystal structure of methionyl-tRNA synthetase from E.coli and obtained the overlay structure after kinetics optimization. Above is the picture showing E.coli methionyl-tRNA synthetase with (left) and without (right) anticodon recognition domain. The picture proposed that E.coli methionyl-tRNA synthetase will lose the ability to bind tRNA^Met anticodon if anticodon recognition domain is deleted, thus losing anticodon specificity while maintaining aminoacylation ability. We have built the truncated MetRS, PT7-metGN (BBa_K567015), based on this design.

Characterization of BBa_K567015

When this part, metY-CGA (BBa_K567016) and KanR (BBa_K567020) are co-transformed into the cell, the cell is expected to survive Kanamycin. We tested the activity of the truncated MetRS PT7-metGN (BBa_K567015)and found that the truncated MetRS acted as expected, losing specificity for tRNA^Met anticodon while maintaining aminoacylation ability.

Fig. Growth of ER2566 with a. metGN + metY-CGA, b. metGM + metY-CGA, c. + metGN, d. + metGM. Growth medium (left): LB Kana+Tet. Growth medium (right): LB Kana.

Cell growth shows that the cells show Kanamycin resistance only when both modified MetRS (metGN) and modified tRNA^Met(metY-CGA) are transformed into the cell, proving that tRNA metY-CGA can transfer fMet to CGA when it is used as the start codon

For more information concerning this part, please see [http://2011.igem.org/Team:SJTU-BioX-Shanghai 2011 SJTU-BioX-iGEM]

Related Biobrick:

PT7-metGM (BBa_K567014)

metY-CGA (BBa_K567016)

Sequence and Features

Assembly Compatibility:

10
INCOMPATIBLE WITH RFC[10]
Illegal EcoRI site found at 1265
Illegal EcoRI site found at 1437
Illegal XbaI site found at 48
12
INCOMPATIBLE WITH RFC[12]
Illegal EcoRI site found at 1265
Illegal EcoRI site found at 1437
Illegal NheI site found at 1226
Illegal NotI site found at 1290
21
INCOMPATIBLE WITH RFC[21]
Illegal EcoRI site found at 1265
Illegal EcoRI site found at 1437
Illegal BamHI site found at 1259
Illegal XhoI site found at 1211
Illegal XhoI site found at 1299
23
INCOMPATIBLE WITH RFC[23]
Illegal EcoRI site found at 1265
Illegal EcoRI site found at 1437
Illegal XbaI site found at 48
25
INCOMPATIBLE WITH RFC[25]
Illegal EcoRI site found at 1265
Illegal EcoRI site found at 1437
Illegal XbaI site found at 48
1000
COMPATIBLE WITH RFC[1000]

@@ Line 2: / Line 2: @@
 <partinfo>BBa_K567015 short</partinfo>
-T7 promoter-''metG''(truncated). This biobrick is constructed by putting the truncated ''metG'' (MetRS) under the control of T7 promoter and lac operator. We have cloned ''metG'' from E.coli and the tRNA recognition domain of MetRS is truncated. KanaR gene with start codon substituted for CGA is used to testify the function of mutated ''metG''. When this biobrick and ''metY''-CGA (BBa_K567016) are co-transformed into the cell, the cells can survive on the LB Kana plate.
+T7 promoter-''metG''(truncated). This biobrick is constructed by putting the truncated ''metG'' (MetRS) under the control of T7 promoter and lac operator. We have cloned ''metG'' from E.coli and the tRNA recognition domain of MetRS is truncated. KanR gene with start codon substituted for CGA is used to testify the function of mutated ''metG''. When this biobrick and ''metY''-CGA (BBa_K567016) are co-transformed into the cell, the cells can survive on the LB Kana plate.
 ===Construction of BBa_K567015===
@@ Line 13: / Line 13: @@
 ===Characterization of BBa_K567015===
-When this part, ''metY''-CGA (BBa_K567016) and KanaR (BBa_K567020) are co-transformed into the cell, the cell is expected to survive Kana. We tested the activity of the truncated MetRS PT7-''metG''N (BBa_K567015)and found that the truncated MetRS acted as expected, losing specificity for tRNA<sup>Met</sup> anticodon while maintaining aminoacylation ability.
+When this part, ''metY''-CGA (BBa_K567016) and KanR (BBa_K567020) are co-transformed into the cell, the cell is expected to survive Kanamycin. We tested the activity of the truncated MetRS PT7-''metG''N (BBa_K567015)and found that the truncated MetRS acted as expected, losing specificity for tRNA<sup>Met</sup> anticodon while maintaining aminoacylation ability.
 [[image:11SJTU-initial_codon_result.jpg|frame|center|Fig. Growth of ER2566 with a. ''metG''N + ''metY''-CGA, b. ''metG''M + ''metY''-CGA, c. + ''metG''N, d. + ''metG''M. Growth medium (left): LB Kana+Tet. Growth medium (right): LB Kana.]]
-Cell growth shows that the cells show Kana resistance only when both modified MetRS (''metG''N) and modified tRNA<sup>Met</sup>(''metY''-CGA) are transformed into the cell,  proving that tRNA ''metY''-CGA can transfer fMet to CGA when it is used as the start codon
+Cell growth shows that the cells show Kanamycin resistance only when both modified MetRS (''metG''N) and modified tRNA<sup>Met</sup>(''metY''-CGA) are transformed into the cell,  proving that tRNA ''metY''-CGA can transfer fMet to CGA when it is used as the start codon
 For more information concerning this part, please see [http://2011.igem.org/Team:SJTU-BioX-Shanghai 2011 SJTU-BioX-iGEM]