Part:BBa_K4006001

arsC

Background

This part contains a protein coding sequence for arsenate reductase that has been codon optimized for use in the chloroplast of Chlamydomonas reinhardtii. Arsenate reductase catalyzes the reduction of arsenate [As(V)] to arsenite [As(III)]. Using 2 µM arsenate at a substrate, the Kcat of the protein has been recorded as 4.5 min(-1). It was introduced into our plasmid backbone MT-pASapI via golden gate assembly.

Cloning into E. coli and Verification

They were transformed into 5-alpha competent E. coli cells from NEB. The cloning was successful, as the positive control plate showed significantly more colonies than the negative control plate.

Figure 1. The plate on the left is the experimental transformation of arsC into plasmid backbone MT-pASapI using Golden Gate Assembly. Multiple individual colonies are present on the plate, indicating successful transformation. The plate on the right is the negative control. Little to no colonies are present on the plate, indicating that there should not be high background or incomplete recombination in our experimental plate.

This was confirmed with a restriction digest of the plasmid using XbaI and BstxI. ArsC was expected to have two bands of sizes 4.4kb and 2.6kb. This is a contrast to the MT-pASapI backbone, which would result in two bands of 4.4kb and 2.3kb. The gel showed three bands for all of the constructs run, the top band being undigested plasmid due to ineffective restriction digest. However, the other bands showed that the inserts contained bands of the appropriate size, and were different from the MT plasmid.

Figure 2. Gel electrophoresis of restriction digest with XbaI and BstXI of original pASapI plasmid, the backbone plasmid with integrated MT used for assembly, and the recombinant colonies with arsC in place of MT. Each of the picked colonies (arsC A-D) indicate three distinct bands as compared to the pASapI's four bands. The top band on each of the constructs is undigested plasmid due to the ineffective SapI enzyme.

Transformation into Chlamydomonas reinhardtii

We were unable to successfully transform this construct into C. reinhardtii.

Sequence and Features

Assembly Compatibility:

• 10
  COMPATIBLE WITH RFC[10]
• 12
  COMPATIBLE WITH RFC[12]
• 21
  COMPATIBLE WITH RFC[21]
• 23
  COMPATIBLE WITH RFC[23]
• 25
  COMPATIBLE WITH RFC[25]
• 1000
  COMPATIBLE WITH RFC[1000]