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Amino acid catabolism

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    Sections/problems listed with an asterisk (*) do not discuss the exact reaction indicated, but do discuss a closely related reaction.

    • Transaminase (EC, EC Section 14.4E
    • Carbamoyl phosphate synthetase (EC P12. 4
    Urea cycle:
    • Ornithine transcarbamylase (EC Section 12.2A,B*
    • Argininosuccinate synthetase (EC Section 12.6, Section 14.1D
    • Arginosuccinate lyase (EC Section 14.1D
    • Arginase (EC P12.16

    Glycine (glycine cleavage system)

    • Glycine dehydrogenase (decarboxylating) (EC P16.4b
    • Aminomethyltransferase (EC C11.5

    Alanine (to pyruvate and glutamate):

    • Alanine transaminase (EC Section 14.4E


    • (to pyruvate): Serine dehydratase (EC Section 13.1B, Section 14.4F
    • (to glycine): Serine hydroxymethyltransferase (EC Section 11.6D, Section 14.4D

    Cysteine (to pyruvate)

    • Cysteine dioxygenase (EC not covered
    • Aspartate aminotransferase ( Section 14.4E


    pathway 1 (to glycine and acetyl CoA):

    • Threonine dehydrogenase (EC Section 16.4D*
    • Glycine C-acetyltransferase (EC Section 14.4D

    pathway 2 (to glycine and acetaldehyde):

    • Threonine aldolase (EC Section 14.4D*, P14.10a

    pathway 3 (to succinyl-CoA via propionyl CoA):

    • Threonine dehydratase (EC P14.2
    • 2-oxobutanoate dehydrogenase (EC Section 16.12B*
    • Propionyl-CoA carboxylase (EC Section 13.5D*, P13.2*
    • Methylmalonyl-CoA mutase (EC not covered

    Tryptophan (to glutaryl-CoA)

    • Tryptophan 2,3-dioxygenase (EC not covered
    • Arylformamidase (EC Chapter 12*
    • Kynurenine 3-monooxygenase (EC Section 16.10
    • Kynurenimase (EC P14.10b
    • 3-hydroxyanthranilate 3,4-dioxygenase (EC not covered
    • Aminocarboxymuconate-semialdehyde decarboxylase (EC Section 13.5C*, P13.5a
    • 2-aminomuconate semialdehyde dehydrogenase (EC Section 16.4D*, P16.2a
    • 2-aminomuconate deaminase (EC Section 11.6*, P11.1
    • 2-oxoglutarate dehydrogenase (EC Section 16.12B*

    Asparagine (to aspartate)

    • Asparaginase (EC Chapter 12*


    • (to oxaloacetate): Aspartate transaminase (EC Section 14.4E
    • (to fumarate): Aspartate-ammonia lyase (EC P14.3

    Glutamine (to glutamate)

    • Glutaminase (EC Chapter 12

    Glutamate (to alpha-ketoglutarate):

    • Glutamate dehydrogenase (EC Section 16.4D

    Arginine (to glutamate):

    • Arginase (EC P12.16b
    • Ornithine transaminase (EC Section 14.4E*
    • Glutamate semialdehyde dehydrogenase (EC Section 16.4D

    Histidine (to glutamate):

    • Histidine ammonia-lyase (EC C14.5
    • Urocanate hydratase (EC C16.1
    • Imidazolonepropionase (EC Chapter 12*
    • Formimidoylglutamase (EC P11.13b

    Valine, isoleucine, leucine:

    • Branched chain amino acid transaminase (EC Section 14.4E*
    • Branched chain ketoacid dehydrogenase complex (EC Section 16.12B*
    • Acyl CoA dehydrogenase (eg. EC Section 16.5C, Section 17.3C

    valine (to succinyl CoA):

    • Enoyl-CoA hydratase (EC P16.9
    • 3-hydroxyisobutyryl-CoA hydrolase (EC P16.9
    • 3-hydroxyisobutyrate dehydrogenase (EC P16.9
    • Methylmalonate-semialdehyde dehydrogenase ( P16.9
    • Propionyl-CoA carboxylase (EC Section 13.5D*, P13.2*
    • Methylmalonyl-CoA mutase (EC not covered

    isoleucine (to succinyl CoA and acetyl CoA):

    • Enoyl-CoA hydratase (EC P16.9
    • Methyl-hydroxybutyryl CoA dehydrogenase (EC Section 16.4*
    • 3-ketoacyl-CoA thiolase (EC Section 13.4B*
    • Propionyl-CoA carboxylase (EC Section 13.5D*, P13.2*
    • Methylmalonyl-CoA mutase (EC not covered

    leucine (to acetyl CoA)

    • Methylcrotonoyl-CoA carboxylase (EC Section 13.5*
    • Methylglutaconyl-CoA hydratase (EC Section 14.1*
    • Hydroxymethylglutaryl-CoA lyase (EC Section 13.3C*

    Methionine (to cysteine and succinyl-CoA):

    • Methionine adenosyltransferase (EC E9.1
    • Methyltransferase (eg. Section 9.1A
    • Adenosylhomocysteinase (EC Section 14.1A
    • Cystathionine beta-synthase (EC Section 14.4G*
    • Cystathionine gamma-lyase (EC Section 14.4G
    • 2-oxobutanoate dehydrogenase (EC Section 16.12B*
    • Propionyl-CoA carboxylase (EC Section 13.5D*, P13.2*
    • Methylmalonyl-CoA mutase (EC not covered

    Lysine (to glutaryl-CoA)

    • Saccharopine dehydrogenase (EC P11.6, P16.7a
    • Saccharopine reductase (EC P11.7, P16.7b
    • Aminoadipate-semialdehyde dehydrogenase (EC Section 16.4D*
    • 2-aminoadipate transaminase (EC2.6.1.39) Section 14.4E*
    • 2-oxoglutarate dehydrogenase (EC Section 16.12B*

    Phenylalanine (to tyrosine):

    • Phenylalanine hydroxylase (EC not covered

    Tyrosine (to fumarate and acetoacetate):

    • Tyrosine transaminase (EC Section 14.4E*
    • 4-hydroxyphenylpyruvate dioxygenase (EC not covered
    • Homogentisate 1,2-dioxygenase (EC not covered
    • Maleylacetoacetate isomerase (EC Section 14.2A*
    • Fumarylacetoacetase (EC Section 13.4B*

    Organic Chemistry With a Biological Emphasis by Tim Soderberg (University of Minnesota, Morris)