Part:BBa_J45001

SAM:salicylic acid carboxyl methyltransferase; converts salicylic acid to methyl salicylate (winter

BBa_J45001 encodes SAM salicylic acid carboxyl methyltransferase I derived from SAMT from Antirrhinus majus (snapdragon). SAMT catalyzes the conversion of salicylic acid to methyl salicylate. Methyl salicylate has a wintergreen smell.

Usage and Biology

• The culture medium of E. coli cells expressing SAMT contained methyl salicylate (2.1 μg/ml) when the growing medium was supplemented with 5 μg/ml salicylic acid, and methyl benzoate (0.86 μg/ml) when the growing medium was supplemented with 5 μg/ml benzoic acid.
• E. coli-expressed SAMT catalyzes the formation of the volatile ester methyl salicylate from salicylic acid with a K_m (salicylic acid) of 83 and a K_m (SAM) of 3-4. SAMT can also methylate benzoic acid to form methyl benzoate, but its K_m value for benzoic acid is 1720 M (much larger). k_cat/K_m for salicylic acid is 132 s^-1 M^-1, and activity with substrate benzoic acid is 45% of the activity with substrate salicylic acid. All other acids yield 0% activity.

Sequence and Features

Assembly Compatibility:

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

  Illegal NheI site found at 577
  
• 21
  INCOMPATIBLE WITH RFC[21]

  Illegal XhoI site found at 901
  
• 23
  COMPATIBLE WITH RFC[23]
• 25
  INCOMPATIBLE WITH RFC[25]

  Illegal NgoMIV site found at 421
  Illegal NgoMIV site found at 425
  
• 1000
  INCOMPATIBLE WITH RFC[1000]

  Illegal SapI site found at 471
  Illegal SapI.rc site found at 75
  

Functional Parameters

ec_num	none
kegg	none
protein	SAMT
swisspro	Q8H6N2