EC - Porphobilinogen synthase

  IntEnz view ENZYME view

IntEnz Enzyme Nomenclature


Accepted name:
porphobilinogen synthase
Other names:
5-levulinic acid dehydratase
δ-aminolevulinate dehydratase
δ-aminolevulinic acid dehydrase
δ-aminolevulinic acid dehydratase
δ-aminolevulinic dehydratase
aminolevulinate dehydratase
aminolevulinic dehydratase
5-aminolevulinate hydro-lyase (adding 5-aminolevulinate and cyclizing)
Systematic name:
5-aminolevulinate hydro-lyase (adding 5-aminolevulinate and cyclizing; porphobilinogen-forming)




The enzyme catalyses the asymmetric condensation and cyclization of two 5-aminolevulinate molecules, which is the first common step in the biosynthesis of tetrapyrrole pigments such as porphyrin, chlorophyll, vitamin B12, siroheme, phycobilin, and cofactor F430. The enzyme is widespread, being essential in organisms that carry out respiration, photosynthesis, or methanogenesis. The enzymes from most organisms utilize metal ions (Zn2+, Mg2+, K+, and Na+) as cofactors that reside at multiple sites, including the active site and allosteric sites. Enzymes from archaea, yeast, and metazoa (including human) contain Zn2+ at the active site. In humans, the enzyme is a primary target for the environmental toxin Pb. The enzymes from some organisms utilize a dynamic equilibrium between architecturally distinct multimeric assemblies as a means for allosteric regulation.

Links to other databases

Enzymes and pathways: NC-IUBMB , BRENDA , DIAGRAM , ExplorEnz , ENZYME@ExPASy , KEGG , MetaCyc , UniPathway
Protein domains and families: PROSITE:PDOC00153
Structural data: CSA , EC2PDB
Gene Ontology: GO:0004655
CAS Registry Number: 9036-37-7
UniProtKB/Swiss-Prot: (59) [show] [UniProt]


  1. Gibson, K.D., Neuberger, A. and Scott, J.J.
    The purification and properties of δ-aminolaevulic acid dehydrase.
    Biochem. J. 61 : 618-629 (1955). [PMID: 13276347]
  2. Komai, H. and Neilands, J.B.
    The metalloprotein nature of Ustilago δ-aminolevulinate dehydratase.
    Biochim. Biophys. Acta 171 : 311-320 (1969). [PMID: 5773436]
  3. Yamasaki, H. and Moriyama, T.
    δ-Aminolevulinic acid dehydratase of Mycobacterium phlei.
    Biochim. Biophys. Acta 227 : 698-705 (1971). [PMID: 4998716]
  4. Mitchell, L. W., Jaffe, E. K.
    Porphobilinogen synthase from Escherichia coli is a Zn(II) metalloenzyme stimulated by Mg(II).
    Arch. Biochem. Biophys. 300 : 169-177 (1993). [PMID: 8424649]
  5. Jaffe, E. K., Ali, S., Mitchell, L. W., Taylor, K. M., Volin, M., Markham, G. D.
    Characterization of the role of the stimulatory magnesium of Escherichia coli porphobilinogen synthase.
    Biochemistry 34 : 244-251 (1995). [PMID: 7819203]
  6. Warren, M. J., Cooper, J. B., Wood, S. P., Shoolingin-Jordan, P. M.
    Lead poisoning, haem synthesis and 5-aminolaevulinic acid dehydratase.
    Trends Biochem. Sci. 23 : 217-221 (1998). [PMID: 9644976]
  7. Jaffe, E. K., Lawrence, S. H.
    Allostery and the dynamic oligomerization of porphobilinogen synthase.
    Arch. Biochem. Biophys. 519 : 144-153 (2012). [PMID: 22037356]
  8. Tian, B. X., Erdtman, E., Eriksson, L. A.
    Catalytic mechanism of porphobilinogen synthase: the chemical step revisited by QM/MM calculations.
    J Phys Chem B 116 : 12105-12112 (2012). [PMID: 22974111]

[EC created 1961]