Part:BBa_K3406005
6xHis/Twin-strep-SUMO-CcaCas13b
CcaCas13b is a member of Cas13 protein family.It has the common characteristic of Type VI RNA-targeting CRISPR–Cas system’s proteins, which means it could be actived by target RNA and could cleave bystander single strained RNAs. This feature could be used to target RNA and thus to detect RNA and to edit RNA. Besides,different Cas13 protein has different base cutting preference,and the preference of CcaCas13b is Poly U/UA/UC
Sequence and Features
- 10COMPATIBLE WITH RFC[10]
- 12COMPATIBLE WITH RFC[12]
- 21INCOMPATIBLE WITH RFC[21]Illegal BamHI site found at 144
- 23COMPATIBLE WITH RFC[23]
- 25INCOMPATIBLE WITH RFC[25]Illegal AgeI site found at 1436
Illegal AgeI site found at 2288 - 1000COMPATIBLE WITH RFC[1000]
Expression and purification
Because CcaCas13b protein was codon optimized, it was expressed in E. coli BL21(DE3). And the expressed protein was purified by Ni-NTA purification.The result is shown below.The molecular weight of CcaCas13b is 143.4 KDa which may be the banding in Lane FT and Lane 10, but the results show that from Lane 50-Lane 500, the banding appears between 41 KDa and 53 KDa. We speculate that the we inserted the 6xHis tag in the wrong site when constructing the part,thus resulting in the discrepancy between the purified protein size and the theoretical value.
Lane M：Protein Marker
Lane FT：Flow through liquid. After the cell lysate was incubated with Ni-NTA agarose
Lane 10：10 mM imidazole eluted protein flow through
Lane 50：50 mM imidazole eluted protein flow through
Lane 250-1 to 250-7：250 mM imidazole first to seventh eluted protein flow-through
Lane 500：500 mM imidazole eluted protein flow through
| None |