Part:BBa_K1195010

T7 Bacteriophage Minor Capsid Protein (Small Mutant 1)

This is the gene that encodes the minor capsid protein in one of our mutant T7 bacteriophage (S4 on our [http://2013.igem.org/Team:BYU_Provo/Results/Experimental results page]). The major capsid protein can also be found in this gene, but it is shorter (The minor capsid protein results from a -1 translation shift towards the end of the major capsid protein). These two capsid proteins make up the external part of T7 bacteriophage's capsid. Our random mutagenesis produced mutations in the gene, which made the capsid size smaller than normal. For this mutant there is a single nucleotide insertion of a G at nucleotide 407. In theory this will create a truncated protein.

Sequence and Features

Assembly Compatibility:

• 10
  COMPATIBLE WITH RFC[10]
• 12
  INCOMPATIBLE WITH RFC[12]

  Illegal NheI site found at 4
  
• 21
  COMPATIBLE WITH RFC[21]
• 23
  COMPATIBLE WITH RFC[23]
• 25
  COMPATIBLE WITH RFC[25]
• 1000
  INCOMPATIBLE WITH RFC[1000]

  Illegal BsaI site found at 292
  Illegal BsaI.rc site found at 497
  

Characterization Data

Sequencing

We discovered that our S4 mutant (discussed above) contain a nucleotide insertion at position 407. In theory, this will lead to premature termination and truncated capsid protein. Below are figures comparing the gene and protein sequences of our mutant phage to that of WT.

Protein Modeling

We tried to map the mutation we discovered. The following are figures displaying the amino acid residue where mutation/frameshift took place. As can be seen from these figures, our mutation are placed at the interface of where capsid proteins interact. In theory, this will alter protein interactions, which will lead to altered capsid size for T7. We are currently working on identifying the mechanism behind this mutation (insertion).

Electron micrograph

The following is one of the electron micrographs that we obtained of our S4 mutant.