Difference between revisions of "Part:BBa J45001"

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===Usage and Biology===
 
===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.  
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*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.
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*'''E. coli'''-expressed SAMT catalyzes the formation of the volatile ester methyl salicylate from salicylic acid with a K<sub>m</sub> (salicylic acid) of 83 and a K<sub>m</sub> (SAM) of 3-4. SAMT can also methylate benzoic acid to form methyl benzoate, but its K<sub>m</sub> value for benzoic acid is 1720 M (much larger). k<sub>cat</sub>/K<sub>m</sub> for salicylic acid is 132 s<sup>-1</sup> M<sup>-1</sup>, and activity with substrate benzoic acid is 45% of the activity with substrate salicylic acid. All other acids yield 0% activity.
  
 
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Revision as of 21:44, 9 March 2008

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 Km (salicylic acid) of 83 and a Km (SAM) of 3-4. SAMT can also methylate benzoic acid to form methyl benzoate, but its Km value for benzoic acid is 1720 M (much larger). kcat/Km 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_numnone
keggnone
proteinSAMT
swissproQ8H6N2