Generator

Part:BBa_I746000

Designed by: David Wyatt   Group: iGEM07_Cambridge   (2007-10-20)
Revision as of 20:43, 21 October 2021 by GU312 (Talk | contribs)

AIP generator (agrB + agrD with RBSes)

This part was made in order to transfer the S. aureus oligopeptide-based quorum sensing system into a BioBrick-compatible signalling mechanism.

In the natural system, the signalling oligopeptide (termed AIP) is made from AgrD by the membrane-located enzyme AgrB. It is then detected by the membrane-located AgrC, which phosphorylates AgrA which then has DNA-binding activity and upregulates transcription of the promoters termed P2 and P3 in the agr locus. There are four known variants of AIP with different molecular structures and cross-inhibitory activity; this BioBrick generates group I AIP.

This part contains the coding regions for group I agrB and agrD (in that order) from S. aureus strain NCTC8325, prefixed by the B0034 RBS and separated by a SaII site.

Further description by BNU-China 2021

1. Different structures of AIP molecules AgrD is transformed into mature AIP through the process of two protease cleavage and a thiolactone formation [1]. So far, it has been found that there are four types of AIP within Staphylococcus aureus (AIP I-IV) in different Staphylococcus aureus [2]. AIP and its receptor are tightly associated and AIP of one certain kind can only specifically activate downstream pathways of corresponding AgrC but inhibit those of other kinds.[4] The structural formulas of four types of AIP are as follows.

Figure 1 The structure of AIPs

2．How AIP inhibits/activates agrC AIP (Autoinducing Peptide) is a short peptide derived from AgrD, which is processed by AgrB to secrete AIP into the extracellular environment. The extracellular AIPs bind to transmembrane proteins AgrC, causing autophosphorylation of AgrC, which then transfers the phosphate to AgrA[1,2]. Phosphorylated AgrA activates the activity of P2 and P3 promoters[2], upregulating the expression of agrABCD and RNA III [3,4]. Figure 2 shows a schematic diagram of the entire system.

Figure 2 Schematic diagram of Agr two-component system

References

[1] Thoendel M, Horswill A R. Biosynthesis of peptide signals in gram-positive bacteria[J]. Advances in Applied Microbiology, 2010, 71(3):91-112.

[2] Lyon G J, Wright J S, Muir T W, et al. Key determinants of receptor activation in the agr autoinducing peptides of Staphylococcus aureus[J]. Biochemistry, 2002, 41: 10095－10104

[3] Novick R P, Projan S J, Kornblum J, et al. The agr P2 operon: an autocatalytic sensory transduction system in Staphylococcus aureus[J]Mol Gen Genet. 1995;248(4):446-458. doi:10.1007/BF02191645

[4] Koenig R L, Ray J L , Maleki S J , et al. Staphylococcus aureus AgrA Binding to the RNAIII-agr Regulatory Region[J]. Journal of Bacteriology, 2004, 186(22):7549-7555.


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]


[edit]
Categories
Parameters
None