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- ***************************************************
- * Porphobilinogen deaminase cofactor-binding site *
- ***************************************************
-
- Porphobilinogen deaminase (EC 4.3.1.8), or hydroxymethylbilane synthase, is an
- enzyme involved in the biosynthesis of porphyrins and related macrocycles. It
- catalyzes the assembly of four porphobilinogen (PBG) units in a head to tail
- fashion to form hydroxymethylbilane.
-
- The enzyme covalently binds a dipyrromethane cofactor to which the PBG
- subunits are added in a stepwise fashion. In the Escherichia coli enzyme (gene
- hemC), this cofactor has been shown [1] to be bound by the sulfur atom of a
- cysteine. The region around this cysteine is conserved in porphobilinogen
- deaminases from various prokaryotic and eukaryotic sources.
-
- -Consensus pattern: E-R-x-[LIVMF]-x(3)-[LIVM]-x-G-[GSA]-C-x-V-P-[LIVM]-[GSA]
- [C is the cofactor attachment site]
- -Sequences known to belong to this class detected by the pattern: ALL.
- -Other sequence(s) detected in SWISS-PROT: NONE.
- -Last update: June 1994 / Pattern and text revised.
-
- [ 1] Miller A.D., Hart G.J., Packman L.C., Battersby A.R.
- Biochem. J. 254:915-918(1988).
-