Coding

Part:BBa_K2924022

Designed by: Arian Abbasi   Group: iGEM19_Duesseldorf   (2019-10-13)


accA

This part contains the coding sequence for the Acetyl-coenzyme A carboxylase carboxyl transferase subunit alpha. 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 1. ACC is allosterically inhibited by the accumulated fatty acyl-CoAs 1.

Usage and Biology

The accA is one of four genes in the composite part AccABCD. The composite part encodes for ACC and catalyzes the first committed step in fatty acid biosynthesis - the ATP-dependent formation of malonyl-CoA from acetyl-CoA and bicarbonate (HCO3-) 1 [Fig. 1]. Fatty acids are carboxylic acids and have a chain length of 4 up to 36 carbon atoms.1

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

AccA encodes the alpha subunit of the Acetyl-coenzyme A carboxylase carboxyl transferase (CT). Together with the beta subunit AccD, they coordinate the transfer of a carboxyl group onto the Acetyl-CoA to convert Malonyl-CoA [Fig. 2]. The gene was replicated 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 1

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
    INCOMPATIBLE WITH RFC[25]
    Illegal AgeI site found at 579
  • 1000
    INCOMPATIBLE WITH RFC[1000]
    Illegal SapI.rc site found at 517
    Illegal SapI.rc site found at 714


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

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