Literature summary for 4.1.99.1 extracted from

Li, G.; Young, K.D.
A new suite of tnaA mutants suggests that Escherichia coli tryptophanase is regulated by intracellular sequestration and by occlusion of its active site (2015), BMC Microbiol., 15, 14 .

Cloned(Commentary)

Cloned (Comment)	Organism
gene tnaA, recombinant expression of wild-type and mutant enzymes in Escherichia coli strain GL619	Escherichia coli

Protein Variants

Protein Variants	Comment	Organism
C352A/Q353A/Q354A	site-directed mutagenesis, the mutation delays TnaA focus disassembly in stationary phase	Escherichia coli
D363A/K366A	site-directed mutagenesis, the mutation does neither affect the enzyme localization nor the enzyme activity	Escherichia coli
D404A	site-directed mutagenesis, the mutation does neither affect the enzyme localization nor the enzyme activity	Escherichia coli
D42A/S43A/E44A/D45A	site-directed mutagenesis, the mutation delays TnaA focus disassembly in stationary phase	Escherichia coli
D49A/T52A/D53A/S54A	site-directed mutagenesis, the mutation delays TnaA focus disassembly in stationary phase	Escherichia coli
E17A/K20A/R21A	site-directed mutagenesis, the mutation does neither affect the enzyme localization nor the enzyme activity	Escherichia coli
E346A/E347A	site-directed mutagenesis, the mutation does neither affect the enzyme localization nor the enzyme activity	Escherichia coli
E384A/K387A/R392A	site-directed mutagenesis, the mutation delays TnaA focus disassembly in stationary phase	Escherichia coli
E416A	site-directed mutagenesis, the mutation alters TnaA focus formation during exponential growth	Escherichia coli
E416A/R419A	site-directed mutagenesis, the mutation alters TnaA focus formation during exponential growth	Escherichia coli
E437A/K440A/H441A	site-directed mutagenesis, the mutation does neither affect the enzyme localization nor the enzyme activity	Escherichia coli
E9A/R12A/R14A	site-directed mutagenesis, the mutation alters TnaA focus formation during exponential growth	Escherichia coli
E9A/R12A/R14A	site-directed mutagenesis, the mutation delays TnaA focus disassembly in stationary phase	Escherichia coli
H370A/D374A/Q375A	site-directed mutagenesis, the mutation does neither affect the enzyme localization nor the enzyme activity	Escherichia coli
K115A	site-directed mutagenesis, the mutation does neither affect the enzyme localization nor the enzyme activity	Escherichia coli
K156A	site-directed mutagenesis, the mutation does neither affect the enzyme localization nor the enzyme activity	Escherichia coli
K239A	site-directed mutagenesis, the mutation does neither affect the enzyme localization nor the enzyme activity	Escherichia coli
K270A	site-directed mutagenesis, the mutation delays TnaA focus disassembly in stationary phase	Escherichia coli
K33A/S34A	site-directed mutagenesis, the mutation does neither affect the enzyme localization nor the enzyme activity	Escherichia coli
K406A/K409A/Q410A	site-directed mutagenesis, the mutation does neither affect the enzyme localization nor the enzyme activity	Escherichia coli
K443A/E444A/N445A/N448A	site-directed mutagenesis, the mutation does neither affect the enzyme localization nor the enzyme activity	Escherichia coli
K450A	site-directed mutagenesis, the mutation does neither affect the enzyme localization nor the enzyme activity	Escherichia coli
K459A	site-directed mutagenesis, the mutation does neither affect the enzyme localization nor the enzyme activity	Escherichia coli
K467A/K469A/E470A	site-directed mutagenesis, the mutation does neither affect the enzyme localization nor the enzyme activity	Escherichia coli
K5A	site-directed mutagenesis, the mutation does neither affect the enzyme localization nor the enzyme activity	Escherichia coli
K5A/K115A/K156A/K239A/K450A/K459A	site-directed mutagenesis, the mutation does neither affect the enzyme localization nor the enzyme activity	Escherichia coli
additional information	construction of 42 TnaA variants: 6 truncated forms and 36 missense mutants in which different combinations of 83 surface-exposed residues are converted to alanine. A truncated TnaA protein containing only domains D1 and D3 (D1D3) localized to the pole. Mutations affecting the D1D3-to-D1D3 interface do not affect polar localization of D1D3 but do delay assembly of wild-type TnaA foci. In contrast, alterations to the D1D3-to-D2 domain interface produce diffuse localization of the D1D3 variant but do not affect the wild-type protein. Altering several surface-exposed residues decreases TnaA activity, implying that tetramer assembly may depend on interactions involving these sites. Changing any of three amino acids at the base of a loop near the catalytic pocket decreases TnaA activity and causes it to form elongated ovoid foci in vivo, indicating that the alterations affect focus formation and may regulate how frequently tryptophan reaches the active site. Mutant phenotypes, detailed overview	Escherichia coli
N327A/D329A	site-directed mutagenesis, the mutation does neither affect the enzyme localization nor the enzyme activity	Escherichia coli
Q339A/Y340A/D343A	site-directed mutagenesis, the mutation does neither affect the enzyme localization nor the enzyme activity	Escherichia coli
Q429A/T430A/H431A/D433A	site-directed mutagenesis, the mutation alters TnaA focus formation during exponential growth	Escherichia coli
R27A/E28A/E29A	site-directed mutagenesis, the mutation delays TnaA focus disassembly in stationary phase	Escherichia coli
R403A	site-directed mutagenesis, the mutation does neither affect the enzyme localization nor the enzyme activity	Escherichia coli
R462A	site-directed mutagenesis, the mutation alters TnaA focus formation during exponential growth	Escherichia coli
R462A/H463A/T465A	site-directed mutagenesis, the mutation alters TnaA focus formation during exponential growth	Escherichia coli
S398A	site-directed mutagenesis, the mutation alters TnaA focus formation during exponential growth	Escherichia coli
S398A	site-directed mutagenesis, the mutation delays TnaA focus disassembly in stationary phase	Escherichia coli
S398A/R403A/D404A	site-directed mutagenesis, the mutation alters TnaA focus formation during exponential growth	Escherichia coli
S398A/R403A/D404A	site-directed mutagenesis, the mutation delays TnaA focus disassembly in stationary phase	Escherichia coli
T23A/R24A/Y26A	site-directed mutagenesis, the mutation does neither affect the enzyme localization nor the enzyme activity	Escherichia coli
T426A/Y427A/T428A	site-directed mutagenesis, the mutation alters TnaA focus formation during exponential growth	Escherichia coli
T453A/T455A/Y456A/E457A	site-directed mutagenesis, the mutation delays TnaA focus disassembly in stationary phase	Escherichia coli
T465A	site-directed mutagenesis, the mutation does neither affect the enzyme localization nor the enzyme activity	Escherichia coli
T60A/Q61A/S62A/Q64A	site-directed mutagenesis, the mutation alters TnaA focus formation during exponential growth	Escherichia coli
T60A/Q61A/S62A/Q64A	site-directed mutagenesis, the mutation delays TnaA focus disassembly in stationary phase	Escherichia coli

Localization

Localization	Comment	Organism	GeneOntology No.	Textmining

Natural Substrates/ Products (Substrates)

Natural Substrates	Organism	Comment (Nat. Sub.)	Natural Products	Comment (Nat. Pro.)	Rev.	Reac.
L-tryptophan + H2O	Escherichia coli	-	indole + pyruvate + NH3	-	r

Organism

Organism	UniProt	Comment	Textmining
Escherichia coli	P0A853	-	-

Source Tissue

Source Tissue	Comment	Organism	Textmining
additional information	the enzyme accumulates as a spherical inclusion (focus) at midcell or at one pole. The D1D3 domain is sufficient for polar localization	Escherichia coli	-

Substrates and Products (Substrate)

Substrates	Comment Substrates	Organism	Products	Comment (Products)	Rev.	Reac.
L-tryptophan + H2O	-	Escherichia coli	indole + pyruvate + NH3	-	r

Subunits

Subunits	Comment	Organism
tetramer	enzyme TnaA probably dimerizes before assembling into the functional tetramer	Escherichia coli

Synonyms

Synonyms	Comment	Organism
TnaA	-	Escherichia coli

Cofactor

Cofactor	Comment	Organism	Structure
pyridoxal 5'-phosphate	dependent on	Escherichia coli

General Information

General Information	Comment	Organism
malfunction	a truncated TnaA protein containing only domains D1 and D3 (D1D3) localizes to the cell pole. Mutations affecting the D1D3-to-D1D3 interface do not affect polar localization of D1D3 but do delay assembly of wild-type TnaA foci. In contrast, alterations to the D1D3-to-D2 domain interface produce diffuse localization of the D1D3 variant but do not affect the wild-type protein. Altering several surface-exposed residues decreases TnaA activity, implying that tetramer assembly may depend on interactions involving these sites. Changing any of three amino acids at the base of a loop near the catalytic pocket decreases TnaA activity and causes it to form elongated ovoid foci in vivo, indicating that the alterations affect focus formation and may regulate how frequently tryptophan reaches the active site. Mutant phenotypes, detailed overview	Escherichia coli
additional information	determination of residues that affect assembly and localization of TnaA foci, overview	Escherichia coli
physiological function	the Escherichia coli enzyme tryptophanase (TnaA) converts tryptophan to indole, which triggers physiological changes and regulates interactions between bacteria and their mammalian hosts. Tryptophanase production is induced by external tryptophan, but the activity of TnaA is also regulated by other mechanisms. TnaA activity is regulated by subcellular localization and by a loop-associated occlusion of its active site, formation of TnaA foci might regulate TnaA function. Model of post-translational regulation of TnaA activity by focus formation, overview	Escherichia coli