Literature summary for 5.1.2.1 extracted from

Desguin, B.; Goffin, P.; Viaene, E.; Kleerebezem, M.; Martin-Diaconescu, V.; Maroney, M.; Declercq, J.; Soumillion, P.; Hols, P.
Lactate racemase is a nickel-dependent enzyme activated by a widespread maturation system (2014), Nat. Commun., 5, 3615 .

Activating Compound

Activating Compound	Comment	Organism	Structure
additional information	lactate racemase is a nickel-dependent enzyme activated by a widespread maturation system. Effect of accessory Lar proteins and cofactors on the in vitro activation of LarANiDELTABCE (apo-LarA) by LarENiBC, overview. Necessity of the Lar accessory proteins (larBCE), for LarA activation. Ni-loaded LarE acts as a maturation protein responsible for the activation of apo-LarA, and indicate that LarB and LarC are involved in the activation of LarE prior to apo-LarA activation	Lactiplantibacillus plantarum

Cloned(Commentary)

Cloned (Comment)	Organism
gene larA, encoded in the lar operon, clustering of lar genes and genotyping, overview. Recombinant expression of N- or C-terminally StrepII-tagged LarA in Lactobacillus lactis	Lactiplantibacillus plantarum

Crystallization (Commentary)

Crystallization (Comment)	Organism
purified enzyme, free or Hg-labeled, hanging drop vapour diffusion method, mixing of 0.002 ml of 16 mg/ml protein solution with 0.002 ml of reservoir solution containing 22% PEG monomethyl ether 5000, 0.2 M ammonium sulfate, 0.1 M MES pH 6.5, 0.2 M sodium malonate pH 7.0 and 0.02% w/v sodium azide, at 18°C, a few days, X-ray diffraction structure determination and analysis at 1.8-2.0 A resolution	Lactiplantibacillus plantarum

Crystallization (Comment)

Organism

purified enzyme, free or Hg-labeled, hanging drop vapour diffusion method, mixing of 0.002 ml of 16 mg/ml protein solution with 0.002 ml of reservoir solution containing 22% PEG monomethyl ether 5000, 0.2 M ammonium sulfate, 0.1 M MES pH 6.5, 0.2 M sodium malonate pH 7.0 and 0.02% w/v sodium azide, at 18°C, a few days, X-ray diffraction structure determination and analysis at 1.8-2.0 A resolution

Lactiplantibacillus plantarum

KM Value [mM]

KM Value [mM]	KM Value Maximum [mM]	Substrate	Comment	Organism	Structure
11	-	(R)-lactate	pH and temperature not specified in the publication	Lactiplantibacillus plantarum
46	-	(S)-lactate	pH and temperature not specified in the publication	Lactiplantibacillus plantarum

Metals/Ions

Metals/Ions	Comment	Organism	Structure
additional information	model of the assembly of the lactate racemase metallocenter, overview. Enzyme LarA receives Ni2+ from the pyridinium-3,5-bisthiocarboxylic acid mononucleotide synthase, LarE (EC 4.4.1.37)	Lactiplantibacillus plantarum
Ni2+	dependent on, nickel is an essential cofactor, the enzyme contains 19-21% nickel, measured by PAR assays and ICP-AES. The LarA Ni center is coordinated by His residues, a four coordinate square planar nickel center or a five coordinate square pyramidal site	Lactiplantibacillus plantarum

Natural Substrates/ Products (Substrates)

Natural Substrates	Organism	Comment (Nat. Sub.)	Natural Products	Comment (Nat. Pro.)	Rev.	Reac.
(S)-lactate	Lactiplantibacillus plantarum	-	(R)-lactate	-	r
(S)-lactate	Lactiplantibacillus plantarum ATCC BAA-793 / NCIMB 8826 / WCFS1	-	(R)-lactate	-	r

Organism

Organism	UniProt	Comment	Textmining
Lactiplantibacillus plantarum	F9USS9	-	-
Lactiplantibacillus plantarum ATCC BAA-793 / NCIMB 8826 / WCFS1	F9USS9	-	-

Purification (Commentary)

Purification (Comment)	Organism
recombinant StrepII-tagged LarA from Lactobacillus lactis by affinity chromatography, gel filtration, and ultrafiltration, to homogeneity. Purification of LarA and LarE can readily be achieved from the strain expressing the entire operon, whereas tagged LarB and LarC can only be purified when the corresponding genes are individually subcloned	Lactiplantibacillus plantarum

Substrates and Products (Substrate)

Substrates	Comment Substrates	Organism	Products	Comment (Products)	Rev.	Reac.
(S)-lactate	-	Lactiplantibacillus plantarum	(R)-lactate	-	r
(S)-lactate	-	Lactiplantibacillus plantarum ATCC BAA-793 / NCIMB 8826 / WCFS1	(R)-lactate	-	r

Subunits

Subunits	Comment	Organism
homodimer	-	Lactiplantibacillus plantarum

Synonyms

Synonyms	Comment	Organism
LARa	-	Lactiplantibacillus plantarum

Temperature Optimum [°C]

Temperature Optimum [°C]	Temperature Optimum Maximum [°C]	Comment	Organism
22	-	assay at room temperature	Lactiplantibacillus plantarum

Turnover Number [1/s]

Turnover Number Minimum [1/s]	Turnover Number Maximum [1/s]	Substrate	Comment	Organism	Structure
1333	-	(R)-lactate	pH and temperature not specified in the publication	Lactiplantibacillus plantarum
4745	-	(S)-lactate	pH and temperature not specified in the publication	Lactiplantibacillus plantarum

General Information

General Information	Comment	Organism
evolution	analysis of the lar gene cluster and its encoded Lar proteins, phylogenetic tree. 92% of the genomes bearing a larA homologue (102 out of 111 genomes) also contain the genes for the Lar accessory proteins (larBCE), further reinforcing the necessity of these proteins for LarA activation	Lactiplantibacillus plantarum
additional information	LarA catalytic site structure analysis in subunits one and two, overview. Structure comparisons to LarA from Thermus thermophilus	Lactiplantibacillus plantarum
physiological function	lactate racemase is a nickel-dependent enzyme activated by a widespread maturation system. Four proteins and Ni are required for in vivo Lar activity. Necessity of the Lar accessory proteins (larBCE), for LarA activation. Ni-loaded LarE acts as a maturation protein responsible for the activation of apo-LarA, and indicate that LarB and LarC are involved in the activation of LarE prior to apo-LarA activation	Lactiplantibacillus plantarum