Phenylacetate Pathway Map

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This pathway was contributed by Lynda Ellis and Shawn Balcome, University of Minnesota.

Phenylacetate is derived from the metabolism of phenylalanine, Z-phenylacetaldoxime, styrene, and many other compounds. Phenylacetate aerobic metabolism in fungi usually proceeds by oxidation to homogentisate (Cox et al., 1996), as shown in the left branch below. In bacteria, this rarely occurs, rather the initial step is ligation with CoA. Pseudomonas putida U uses both pathways; 4-hydroxyphenylacetate is metabolised via oxidation and phenylacetate via ligation with CoA (Olivera et al., 1994). Ligation is followed by epoxide formation, isomerization of the epoxide to an oxepin, and hydrolytic ring cleavage, to eventually produce acetyl-CoA and succinyl-CoA, as shown in the right branch. This pathway is found in 16% of 640 bacteria whose genomes have been sequenced, including Pseudomonas putida and Escherichia coli (Teufel et al., 2010).

Under anaerobic conditions, the denitrifying bacterium Thauera aromatica oxidizes phenylacetate to benzoyl-CoA via the intermediates phenylacetyl-CoA and phenylglyoxylate (benzoylformate) (Rhee and Fuchs, 1999). This pathway is shown in the KEGG database.

The following is a text-format aerobic phenylacetate pathway map. Organisms which can initiate the pathway are given, but other organisms may also carry out later steps. Follow the links for more information on compounds or reactions. This map is also available in graphic (8k) format.

                                 from the 
                           Z-Phenylacetaldoxime,   
                           Styrene and Atropine
       Phenylacetate <---------  Pathways  ---------> Phenylacetate
    Exophiala jeanselmei                            Pseudomonas putida
      and many others                                and many others
             |                                              |  
             | phenylacetate                                | phenylacetate--CoA
             | hydroxylase                                  | ligase
             |                                              |
             v                                              v
  2-Hydroxyphenylacetate                             Phenylacetyl-CoA
             |                                              |
             | 2-hydroxyphenyl-                             | phenylacetyl-CoA
             | acetate hydroxylase                          | monooxygenase
             |                                              |
             v                                              v
       Homogentisate                            1,2-Epoxyphenylacetyl-CoA
             |                                              |
             |                                              | 1,2-epoxyphenylacetyl-CoA
             v                                              | isomerase
           to the                                           |
          Tyrosine                                          v
          Pathway                              2-[(2E)-2,3-dihydrooxepin-
                                                  2-ylidene]acetyl-CoA
                                                            |
                                                            | 2-oxepin-2(3H)-ylidene-
                                                            | acetyl-CoA hydrolase
                                                            v
                                              3-oxo-5,6-dehydrosuberyl-CoA
                                                            |
                                                            |
                                                            | 3-oxo-5,6-dehydrosuberyl-CoA
                                                            | thiolase
                                                            |
                                                            v
                                                5-Carboxy-2-pentenoyl-CoA               
                                                            |
                                                            |
                                                            |
                                                            v
                                                          to the
                                                       Cyclohexane
                                                         Pathway

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Page Author(s): Dean Kraus, Andrea Marconi, Kenneth E. Lind, Ryan McLeish, Lynda Ellis

July 11, 2017 Contact Us

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