Literature summary for 5.1.1.21 extracted from

Awad, R.; Gans, P.; Reiser, J.B.
Structural insights into the substrate recognition and reaction specificity of the PLP-dependent fold-type I isoleucine 2-epimerase from Lactobacillus buchneri (2017), Biochimie, 137, 165-173 .

Cloned(Commentary)

Cloned (Comment)	Organism
recombinant expression of codon-optimized, His-tagged enzyme in Escherichia coli strain BL21(DE3)	Lentilactobacillus buchneri

Crystallization (Commentary)

Crystallization (Comment)	Organism
purified recombinant His-tagged enzyme alone or in complex with pyridoxal 5'-phosphate, hanging drop vapour diffusion technique, mixing of 0.002 ml of 2-8 mg/ml protein in 50 mM Na-phosphate, pH 7.2, and 0.1 mM 2-mercaptoethanol, with 0.002 ml of reservoir solution containing 12-18% PEG 3350 and 100 mM lithium citrate, 20°C, several weeks, for complex crystals soaking in pyridoxal 5'-phosphate containing mother liquor, X-ray diffraction structure determination and analysis at 2.6 A and 2.15 A resolution, respectively	Lentilactobacillus buchneri

Crystallization (Comment)

Organism

purified recombinant His-tagged enzyme alone or in complex with pyridoxal 5'-phosphate, hanging drop vapour diffusion technique, mixing of 0.002 ml of 2-8 mg/ml protein in 50 mM Na-phosphate, pH 7.2, and 0.1 mM 2-mercaptoethanol, with 0.002 ml of reservoir solution containing 12-18% PEG 3350 and 100 mM lithium citrate, 20°C, several weeks, for complex crystals soaking in pyridoxal 5'-phosphate containing mother liquor, X-ray diffraction structure determination and analysis at 2.6 A and 2.15 A resolution, respectively

Lentilactobacillus buchneri

Molecular Weight [Da]

Molecular Weight [Da]	Molecular Weight Maximum [Da]	Comment	Organism
200000	-	recombinnat His-tagged enzyme, gel filtration	Lentilactobacillus buchneri

Natural Substrates/ Products (Substrates)

Natural Substrates	Organism	Comment (Nat. Sub.)	Natural Products	Comment (Nat. Pro.)	Rev.	Reac.
L-isoleucine	Lentilactobacillus buchneri	-	D-allo-isoleucine	-	r
L-isoleucine	Lentilactobacillus buchneri JCM 1115	-	D-allo-isoleucine	-	r

Organism

Organism	UniProt	Comment	Textmining
Lentilactobacillus buchneri	M1GRN3	-	-
Lentilactobacillus buchneri JCM 1115	M1GRN3	-	-

Purification (Commentary)

Purification (Comment)	Organism
recombinant His-tagged enzyme from Escherichia coli strain BL21(DE3) by nickel affinity chromtography and gel filtration	Lentilactobacillus buchneri

Reaction

Reaction	Comment	Organism	Reaction ID
L-isoleucine = D-allo-isoleucine	the racemization reaction by the fold-type I racemases may generally occur thanks to a revised two-base mechanism. Conformational changes provoked by pyridoxal 5'-phosphate binding suggesting an induced fit of the active site entrance door necessary to accommodate pyridoxal 5'-phosphate and substrate molecules	Lentilactobacillus buchneri	a

Substrates and Products (Substrate)

Substrates	Comment Substrates	Organism	Products	Comment (Products)	Rev.
L-isoleucine	-	Lentilactobacillus buchneri	D-allo-isoleucine	-	r
L-isoleucine	-	Lentilactobacillus buchneri JCM 1115	D-allo-isoleucine	-	r
additional information	the enzyme catalyzes the pyridoxal 5'-phosphate (PLP)-dependent racemization and epimerization of a broad spectrum of nonpolar amino acids from L- to D-form and vice versa, in particular isoleucine	Lentilactobacillus buchneri	?	-	?
additional information	the enzyme catalyzes the pyridoxal 5'-phosphate (PLP)-dependent racemization and epimerization of a broad spectrum of nonpolar amino acids from L- to D-form and vice versa, in particular isoleucine	Lentilactobacillus buchneri JCM 1115	?	-	?

Synonyms

Synonyms	Comment	Organism
BCAA racemase	UniProt	Lentilactobacillus buchneri
isoleucine 2-epimerase	-	Lentilactobacillus buchneri
PLP-dependent fold-type I isoleucine 2-epimerase	-	Lentilactobacillus buchneri

Cofactor

Cofactor	Comment	Organism	Structure
pyridoxal 5'-phosphate	PLP, dependent on	Lentilactobacillus buchneri

General Information

General Information	Comment	Organism
evolution	the enzyme belongs to the fold-type I subgroup of pyridoxal 5'-phosphate-dependent enzymes and is very close to aminobutyrate aminotransferases family	Lentilactobacillus buchneri
additional information	identification of the active site residues responsible for its nonpolar amino acid recognition and reactivity specificity from structure comparisons with the alpha-amino-epsilon-caprolactam racemase (EC 5.1.1.15) from Achromobacter obae and the cystathionine beta-lyase (EC 4.4.1.8) from Escherichia coli (PDB IDs 2ZUK and 3DXW), active site structure, overview	Lentilactobacillus buchneri