Part:BBa_K1660000

Introduction

A serine protease bace16 was first reported as a pathogenic factor against nematodes, whose accession number is AY708655. It was identified by methods such as ammonium sulfate precipitation. [1] In vitro assay demonstrated that the recombinant protease Bace16 expressed in Escherichia coli presented a nematotoxic activity, and it has been verified by experiments that Bace16 has the ability to degrade a nematode cuticle, leading to the nematode’s death.[2] Bace16 could be considered as a core component to kill the nematode.

Sequence and Features

Assembly Compatibility:

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

  Illegal NheI site found at 125
  
• 21
  INCOMPATIBLE WITH RFC[21]

  Illegal BamHI site found at 65
  Illegal XhoI site found at 151
  
• 23
  COMPATIBLE WITH RFC[23]
• 25
  INCOMPATIBLE WITH RFC[25]

  Illegal NgoMIV site found at 247
  Illegal NgoMIV site found at 610
  Illegal NgoMIV site found at 682
  Illegal NgoMIV site found at 934
  Illegal AgeI site found at 541
  
• 1000
  COMPATIBLE WITH RFC[1000]

Structure

The molecular mass of a mature Bace16 protein is about 28kDa. And the protein has 275 residues, with a catalytic triad center containing His, Asp, and Ser residues and two calcium binding sites for stabilizing the three-dimensional structure. Characterization of the purified protease revealed the optimum activity of Bace16 is at pH10, 50℃. The deduced protein also contains a presequence signal peptide of 30 amino acids and a propeptide of 77 amino acids. The presequence signal peptide directs the secretion of subtilisin from the interior of cells, while the propeptide functions as a chaperon to facilitate the folding process of the active protease.[3]

Figure 1 Expression and purification of ModA. Expression of ModA and its purification by His-chelating chromatography. Lane 1, molecular weight standards (kDa); lane 2, total bacterial proteins before IPTG induction; lane 3, total bacterial proteins after 0.5 mM IPTG induction; lane 4, total bacterial lysate after 0.5 mM IPTG induction; lane 5,the sediment after 16,000 rpm 30 min; lane 6 the flow through of column loading; lane 7,the flow of buffer B .lane 8 The purification of ModA by size-elution chromatography.

Figure 2 Native-PAGE to provide the molybdate lane 1, the modA(acetic buffer PH 5.0); lane 2, the modA incubate with 20mM molybdate.