Part:BBa_K3731000

ppk1 in E.Coli BL21

In bacteria, polyP is synthesized by polyphosphate kinase (PPK). PPK consists of PPK1 and PPK2. PPK1 can lengthen the polymer by using the γ-Pi phosphate bond of ATP, and its reversible reaction is to synthesize ATP from ADP and Pi. PPK2 can use polyP to synthesize GTP or ATP reversibly, and mainly synthesize GTP. The ppk1 codes PPK1, which can promote the synthesis(major function) and decomposition(minor function) of polyP with the residue of ATP.

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]

iGEM2021_Nanjing-China Experiment

Group: Nanjing-China 2021
Author: Hao Yin

Polyphosphate kinase(PPK) polymerizes the terminal phosphate of ATP to a long chain of polyphosphate(polyP) in a freely reversible reaction. Here polyphosphate kinase was purified and characterized by SDS-PAGE. Bands of 69kDa showed the existence of PPK in the Escherichia coli.

Figure1 SDS-PAGE analysis of PPK

Additionally, efficiency of polyP synthesis by PPK was measured at 1mM ATP. As shown in the diagram, polyP synthesis was linear with time for about 40 min. However, if the concentration of ATP is lower than 5 μM, there is virtually no synthesis of polyP for 20 min.

Figure2 Time course of polyP synthesis at 1mM ATP

Reference: Kyunghye Ahn and Arthur Kornberg. Polyphosphate Kinase from Escherichia coli[J]. The Journal of Biological Chemistry, 1990, 265, 20, 11734-11739.