Part:BBa_K1378003

Microvirin (MVN)---a lectin from Microcystis aeruginosa

Improved by Fudan iGEM 2023

Intimin which includes a short N-terminal signal peptide to direct its trafficking to the periplasm, a LysM domain for peptidoglycan binding, and a beta-barrel for transmembrane insertion , possesses the outer membrane anchoring of MVN.Instead of using INPNC-MVN fusion, we introduce intimin as a surface display system to present MVN, thus facilitating adhesion between E. coli and Microcystis aeruginosa PCC7806.

Improved part

Our improved part is BBa_K4765109 (Twister P1 + T7_RBS + intimin-MVN fusion + stem-loop) . We introduce intimin as a surface display system to present MVN and construct this part into our ribozyme-assisted polycistronic co-expression system.

Introduction

This plasmid is a basic part of the mannan binding lectin Microvirin (MVN). Microvirin can be expressed in E. coli and it can bind to Microcystis aeruginosa PCC7806 specifically.

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
  INCOMPATIBLE WITH RFC[1000]

  Illegal SapI site found at 23
  

Usage and Biology

MVN is a lectin isolated from the cyanobacteria Microcystis aeruginosa PCC7806. It is an 108 aa protein that consists of 2 domains. According to a carbohydrate microarray carried out previously, MVN binds to carbohydrate and the highest signals are observed with structures that contain α(1→2) linked mannose residues ^[1]. A binding partner of MVN was identified in the lipopolysaccharide (LPS) fraction of M. aeruginosa PCC7806 and it possibly represents the O-antigen of a LPS. MVN has been previously expressed in E. coli and its binding effect to cyanobacteria cells is species-specific ^[1].

Figure 1. Solution structure of MVN. MVN consists of 2 domains, domain A and domain B, which are colored yellow and blue respectively. Domain A is formed by residues 38-93 while domain B is formed by residues 1-37 and 94-108. The mannan binding site is only found in domain A. This figure is taken from Protein Data Bank (PDB ID: 2Y1S).

Reference

1.Kehr, J. C., Zilliges, Y., Springer, A., Disney, M. D., Ratner, D. D., Bouchier, C., ... & Dittmann, E. (2006). A mannan binding lectin is involved in cell–cell attachment in a toxic strain of Microcystis aeruginosa. Molecular microbiology, 59(3), 893-906.