Part:BBa_K3724008

Diguanylate cyclase YdeH

Usage and Biology

Shewanella oneidensis MR-1 are gram-negative bacteria at the center of studies of microbial reduction due to their ability to transfer electrons extracellularly to reduce materials such as graphene oxide (GO)[1]. Two extracellular electron transfer pathways have been identified in the reduction of GO by Shewanella oneidensis MR-1. These are indirect electron transfer, mediated by secreted electron shuttles, and direct extracellular electron transfer (DET) which involves direct contact with the extracellular material [2]. Electron transfer via the DET pathway can be made more efficient by promoting biofilm formation. ydeH in Escherichia coli is a diguanylate cyclase which catalyzes the synthesis of Bis-(3′-5′)-cyclic dimeric guanosine monophosphate (c-di-GMP) from two molecules of Guanosine-5'-triphosphate (GTP). c-di-GMP is an intracellular signalling molecule that, if in high concentrations within the cell, helps in promoting bacterial biofilm production.[3] It has previously been seen that overexpression of ydeH in S. oneidensis MR-1 leads to an increase in bioelectricity generation and biofilm production [4]. An increase in bioelectricity generation signifies an increase in extracellular electron transfer so we thought that overexpressing this gene in S.oneidensis MR-1 would lead to increased extracellular electron transfer which in turn would lead to increased reduction of GO as compared to wild type MR-1.The exact mechanism by which the electron transfer is increased has not been elucidated but it is thought that increased biofilm production increases point of contact with the extracellular material allowing for more transfer of electrons via outer membrane cytochrome proteins.

We therefore, synthesized the ydeH gene, optimized for S. oneidensis MR-1 , and inserted it into the kanamycin resistant vector pcD8 under the control of an IPTG-inducible promoter (Keitz lab, University of Texas Austin) [5].

References

Sequence and Features

Assembly Compatibility:

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

  Illegal XhoI site found at 10
  
• 23
  COMPATIBLE WITH RFC[23]
• 25
  COMPATIBLE WITH RFC[25]
• 1000
  INCOMPATIBLE WITH RFC[1000]

  Illegal BsaI site found at 7
  Illegal BsaI.rc site found at 910