ID   4.2.1.24
DE   porphobilinogen synthase.
AN   aminolevulinate dehydratase.
AN   delta-aminolevulinic acid dehydratase.
CA   2 5-aminolevulinate = H(+) + 2 H2O + porphobilinogen.
CC   -!- The enzyme catalyzes the asymmetric condensation and cyclization of
CC       two 5-aminolevulinate molecules, which is the first common step in
CC       the biosynthesis of tetrapyrrole pigments such as porphyrin,
CC       chlorophyll, vitamin B12, siroheme, phycobilin, and cofactor F430.
CC   -!- The enzyme is widespread, being essential in organisms that carry out
CC       respiration, photosynthesis, or methanogenesis.
CC   -!- In humans, the enzyme is a primary target for the environmental toxin
CC       Pb.
CC   -!- The enzymes from some organisms utilize a dynamic equilibrium between
CC       architecturally distinct multimeric assemblies as a means for
CC       allosteric regulation.
DR   Q9SFH9, HEM21_ARATH;  Q94LA4, HEM22_ARATH;  O67876, HEM2_AQUAE ;
DR   O28305, HEM2_ARCFU ;  P30950, HEM2_BACSU ;  Q58DK5, HEM2_BOVIN ;
DR   P45622, HEM2_BRADU ;  O42768, HEM2_CANGA ;  Q9PLU4, HEM2_CHLMU ;
DR   Q59334, HEM2_CHLP8 ;  Q9Z7G1, HEM2_CHLPN ;  Q42682, HEM2_CHLRE ;
DR   Q8KCJ0, HEM2_CHLTE ;  O84638, HEM2_CHLTR ;  Q55E06, HEM2_DICDI ;
DR   P0ACB2, HEM2_ECOLI ;  Q750E0, HEM2_EREGS ;  Q9K8G2, HEM2_HALH5 ;
DR   Q9ZMR8, HEM2_HELPJ ;  P56074, HEM2_HELPY ;  Q42836, HEM2_HORVU ;
DR   P13716, HEM2_HUMAN ;  Q60HH9, HEM2_MACFA ;  Q60178, HEM2_METJA ;
DR   Q02250, HEM2_METSC ;  O26839, HEM2_METTH ;  P10518, HEM2_MOUSE ;
DR   P46723, HEM2_MYCLE ;  P9WMP4, HEM2_MYCTO ;  P9WMP5, HEM2_MYCTU ;
DR   Q5Z8V9, HEM2_ORYSJ ;  P30124, HEM2_PEA   ;  Q43058, HEM2_PHYPA ;
DR   Q5R971, HEM2_PONAB ;  P77923, HEM2_PROFF ;  Q59643, HEM2_PSEAE ;
DR   P06214, HEM2_RAT   ;  P42504, HEM2_RHOCA ;  Q59295, HEM2_RUMJO ;
DR   P78974, HEM2_SCHPO ;  P45623, HEM2_SELMA ;  P0ACB3, HEM2_SHIFL ;
DR   P43210, HEM2_SOYBN ;  P24493, HEM2_SPIOL ;  Q2FXR3, HEM2_STAA8 ;
DR   Q5HFA4, HEM2_STAAC ;  P64333, HEM2_STAAM ;  P64334, HEM2_STAAN ;
DR   Q6GG37, HEM2_STAAR ;  Q6G8Q7, HEM2_STAAS ;  P0C1R9, HEM2_STAAU ;
DR   P64335, HEM2_STAAW ;  Q5HNN5, HEM2_STAEQ ;  Q8CNZ0, HEM2_STAES ;
DR   P54919, HEM2_STRCO ;  P43087, HEM2_SYNE7 ;  P77969, HEM2_SYNY3 ;
DR   P05373, HEM2_YEAST ;
//