Part:BBa_K2717013

TorA signal-VHb

Vitreoscilla haemoglobin (VHb) is a type of haemoglobin found in the Gram-negative aerobic bacterium, Vitreoscilla. It is the first haemoglobin discovered from bacteria. Vitreoscilla is a type of aerobic bacteria, but it mainly lives in a low-oxygen environment such as a swamp. VHb can help Vitreoscilla enrich oxygen , ensuring that vitreoscilla gets enough oxygen. Previous studies have shown that the expression of VHb in the periplasmic space of Gram-negative bacteria can significantly increase the ability of Gram-negative bacteria to obtain oxygen, thereby promoting their growth. In most Gram-negative bacteria, including E. coli, there is a system for transporting proteins to the periplasmic space, the TAT system, which transports proteins to different locations by recognizing different signal sequences. The TorA signal sequence is a sequence of 42 amino acids. Studies have shown that the TAT system transports the protein to the periplasmic space by recognizing the TorA sequence preceding the target protein. Therefore, at the part we constructed, we placed the TorA sequence in front of VHb. When our part is normally expressed, we can express VHb protein in the periplasmic space of Gram-negative bacteria, Thereby achieving its ability to obtain oxygen.

This part is improved from BBa_K1321200. In this part, a periplasmic signal peptide TorA is added to the N-terminus of hemoglobin isolated from Vitreoscilla (VHb) （from BBa_K1321200）. Vhb itself can improve the rate of oxidative phosphorylation and increase cell metabolism. Meanwhile, according to a recent paper, vhb can work more efficiently when it is transported to cell’s periplasm. Our improvement successfully increase the growth-promotion effect of Vhb.

function:This part can accelerate the cell metabolism and make the bacteria grow faster.

Sequence and Features

Assembly Compatibility:

• 10
  COMPATIBLE WITH RFC[10]
• 12
  COMPATIBLE WITH RFC[12]
• 21
  INCOMPATIBLE WITH RFC[21]

  Illegal BglII site found at 540
  
• 23
  COMPATIBLE WITH RFC[23]
• 25
  COMPATIBLE WITH RFC[25]
• 1000
  COMPATIBLE WITH RFC[1000]

IMPROVEMENT REFERENCE: BNU_China 2018

The new part is improved from a original part: BBa_K1321200 (Group: iGEM14_Imperial).