Any feedback?
Please rate this page
(all_enzymes.php)
(0/150)

BRENDA support

4.1.99.2: tyrosine phenol-lyase

This is an abbreviated version!
For detailed information about tyrosine phenol-lyase, go to the full flat file.

Word Map on EC 4.1.99.2

Reaction

L-tyrosine
+
H2O
=
phenol
 +
pyruvate
 +
NH3

Synonyms

beta-tyrosinase, Fn-TPL, L-tyrosine phenol-lyase, phenol-lyase, tyrosine, TnaA, TPL, tyrosine phenol lyase, tyrosine phenol-lyase, tyrosine-phenol lyase

ECTree

     4 Lyases
         4.1 Carbon-carbon lyases
             4.1.99 Other carbon-carbon lyases
                4.1.99.2 tyrosine phenol-lyase

General Information

General Information on EC 4.1.99.2 - tyrosine phenol-lyase

Please wait a moment until all data is loaded. This message will disappear when all data is loaded.
GENERAL INFORMATION
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
evolution
the carbon-carbon lyases, tryptophan indole lyase (TIL, EC 4.1.99.1) and tyrosine phenol-lyase (TPL) are bacterial enzymes which catalyze the reversible elimination of indole and phenol from L-tryptophan and L-tyrosine, respectively. These pyridoxal 5'-phosphate-dependent enzymes show high sequence homology (about 40% identity) and both form homotetrameric structures. Pre-steady state kinetics with TPL and TIL show rapid formation of external aldimine intermediates, followed by deprotonation to give quinonoid intermediates absorbing at about 500 nm. The active sites of TIL and TPL are highly conserved with the exceptions of these residues: Arg381(TPL)/Ile396 (TIL), Thr124 (TPL)/Asp137 (TIL), and Phe448 (TPL)/His463 (TIL). The conserved tyrosine, Tyr71 (TPL)/Tyr74 (TIL) is essential for elimination activity with both enzymes, and likely plays a role as a proton donor to the leaving group.A unique feature of TIL and TPL is another strictly conserved lysine (Lys256 in Citrobacter freundii TPL) immediately preceding the pyridoxal 5'-phosphate-binding lysine, and hydrogen bonded to a water molecule bound to the monovalent cation. The mechanisms of TPL and TIL require both substrate strain and acid/base catalysis, and substrate strain is probably responsible for the very high substrate specificity of TPL and TIL. Both enzymes require a monovalent cation, either K+, NH4+, Rb+ or Cs+ for activity, with Na+ and Li+ giving little or no activity. The active site residues involved in PLP binding are highly conserved for both TIL and TPL. Sequence comparisons
metabolism
-
tyrosine phenol lyase catalyses the biosynthesis of L-tyrosine/L-DOPA from ammonium, pyruvate and phenolic substrates through the reverse of alpha- and beta-elimination reaction
physiological function
-
hyper-3,4-dihydroxyphenyl-L-alanine-producing strain by a mutant TyrR, an activator of tpl, whereby highest productivity is obtained for the strain grown under non-induced conditions, which is 30fold higher than that obtained for tyrosine-induced wild-type cells
additional information