Part:BBa_K2924025

accD

This part contains the coding sequence for the Acetyl-coenzyme A carboxylase carboxyl transferase subunit beta. It is a component of the Acetyl-CoA carboxylase complex (ACC) from Escherichia coli (strain K12), involved in the fatty acid biosynthesis. Cloned into an inducible pET21a (Novagen) vector carrying an ampicillin resistance and containing strong T7 promoter and C-terminal histidine tag. ACC is allosterically inhibited by the accumulated fatty acyl-CoAs ^1.

Usage and Biology

The gene accD encodes the beta subunit of the Acetyl-coenzyme A carboxylase carboxyl transferase (CT). Together with the alpha subunit (accA), the transfer a carboxyl group onto the Acetyl-CoA to synthesize Malonyl-CoA [Fig. 2]. The gene accD was replicated E. coli DH5a and overexpressed in E. coli BL21 to increase carbon flux towards the precursor malonyl-CoA. An improved cellular concentration of Malonyl-CoA contributes to increased production of malonyl-CoA derived compounds like fatty acids ⁴.

Fig. 1: Biosynthesis of fatty acids. ACC-catalyzed formation of Malonyl-CoA from bicarbonate and Acetyl-CoA under the hydrolysis of ATP

The gene accD encodes the beta subunit of the Acetyl-coenzyme A carboxylase carboxyl transferase (CT). Together with the alpha subunit (accA), the transfer a carboxyl group onto the Acetyl-CoA to synthesize Malonyl-CoA [Fig. 2]. The gene accD was replicated E. coli DH5a and overexpressed in E. coli BL21 to increase carbon flux towards the precursor malonyl-CoA. An improved cellular concentration of Malonyl-CoA contributes to increased production of malonyl-CoA derived compounds like fatty acids ⁴.

Fig. 2: Bacterial fatty acid synthesis pathway in E. coli. AccAD is highlighted and represents the two genes AccA and AccD involved in the CT. Modified from Christoph Freiberg et al., 2014

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]

References

[1] Faergeman, Nils Joakim, and Jens Knudsen. "Role of long-chain fatty acyl-CoA esters in the regulation of metabolism and in cell signalling." Biochemical Journal 323.Pt 1 (1997): 1.

[2] Fujita, Yasutaro, Hiroshi Matsuoka, and Kazutake Hirooka. "Regulation of fatty acid metabolism in bacteria." Molecular microbiology 66.4 (2007): 829-839.

[3] Lehninger, A. L., Nelson, D. L., Cox, M. M., & Osgood, M. (2005). Lehninger principles of biochemistry. New York: W.H. Freeman.

[4] Choi-Rhee, Eunjoo, and John E. Cronan. "The biotin carboxylase-biotin carboxyl carrier protein complex of Escherichia coli acetyl-CoA carboxylase." Journal of Biological Chemistry 278.33 (2003): 30806-30812.

[5] Xu, Peng, et al. "Modular optimization of multi-gene pathways for fatty acids production in E. coli." Nature communications 4 (2013): 1409.