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

BRENDA support

Literature summary for 5.1.1.18 extracted from

  • Shrestha, R.; Lockless, S.W.; Sorg, J.A.
    A Clostridium difficile alanine racemase affects spore germination and accommodates serine as a substrate (2017), J. Biol. Chem., 292, 10735-10742 .
    View publication on PubMedView publication on EuropePMC
Search for more literature for 5.1.1.18

Cloned(Commentary)

Cloned (Comment) Organism
gene alr2, recombinant expression of wild-type and mutant enzymes in Escherichia coli strain BL21(DE3) Clostridioides difficile

Protein Variants

Protein Variants Comment Organism
K39A site-directed mutagenesis, kinetically inactive mutant, the mutation disrupts the binding of the co-factor that is essential for catalysis (pyridoxal 5'-phosphate), the mutant shows altered binding kinetics with L-alanine and D-alanine, weak binding to L- and D-serine Clostridioides difficile

KM Value [mM]

KM Value [mM] KM Value Maximum [mM] Substrate Comment Organism Structure
14
-
 L-serine pH 7.5, 37°C, recombinant wild-type enzyme Clostridioides difficile
17
-
 L-serine pH 7.5, 37°C, recombinant mutant K39A Clostridioides difficile

Natural Substrates/ Products (Substrates)

Natural Substrates Organism Comment (Nat. Sub.) Natural Products Comment (Nat. Pro.) Rev. Reac.
L-serine Clostridioides difficile
-
 D-serine
-
 r
L-serine Clostridioides difficile UK1
-
 D-serine
-
 r

Organism

Organism UniProt Comment Textmining
Clostridioides difficile
-
 i.e. Peptoclostridium difficile
-
Clostridioides difficile UK1
-
 i.e. Peptoclostridium difficile
-

Purification (Commentary)

Purification (Comment) Organism
recombinant wild-type and mutant enzymes from Escherichia coli strain BL21(DE3) by nickel affinity chromatography, dialysis, and gel filtration Clostridioides difficile

Substrates and Products (Substrate)

Substrates Comment Substrates Organism Products Comment (Products) Rev. Reac.
L-serine
-
 Clostridioides difficile D-serine
-
 r
L-serine alanine racemase 2, Alr2, converts L-serine to an approximately equal amount of D-serine. When tested with D-serine, Alr2 does not convert as much, and nearly 75% of the D-serine remains in the D-form Clostridioides difficile D-serine
-
 r
L-serine
-
 Clostridioides difficile UK1 D-serine
-
 r
L-serine alanine racemase 2, Alr2, converts L-serine to an approximately equal amount of D-serine. When tested with D-serine, Alr2 does not convert as much, and nearly 75% of the D-serine remains in the D-form Clostridioides difficile UK1 D-serine
-
 r

Temperature Optimum [°C]

Temperature Optimum [°C] Temperature Optimum Maximum [°C] Comment Organism
37
-
 assay at Clostridioides difficile

pH Optimum

pH Optimum Minimum pH Optimum Maximum Comment Organism
7.5
-
 assay at Clostridioides difficile

Cofactor

Cofactor Comment Organism Structure
pyridoxal 5'-phosphate dependent on Clostridioides difficile

General Information

General Information Comment Organism
additional information Alr2 racemase is the sixth most highly expressed gene during Clostridium difficile spore formation Clostridioides difficile
physiological function many endospore-forming bacteria embed alanine racemases into their spore coats, and these enzymes are thought to convert the L-alanine germinant into D-alanine, a spore germination inhibitor. Clostridium difficile spores can respond to a diverse set of amino acid co-germinants and alanine racemase 2, Alr2, EC 5.1.1.1, can accommodate serine as a substrate. L-alanine is a co-germinant, and D-alanine also functions as a co-germinant. L- and D-serine are also co-germinants for Clostridium difficile spores. Only the L-form of alanine can trigger spore germination when added with taurocholic acid. Gene alr2 is dispensable for germination in response to L-alanine but essential for germination in response to D-alanine Clostridioides difficile