the 1.45Å a crystal structure of alanine racemase from a pathogenic bacterium, pseudomonas aeruginosa, contains both internal and external aldimine forms
Identifiers
Symbol
Ala_racemase_N
Pfam
PF01168
Pfam clan
CL0036
InterPro
IPR001608
PROSITE
PDOC00332
SCOP2
1sft / SCOPe / SUPFAM
Available protein structures:
Pfam
structures / ECOD
PDB
RCSB PDB; PDBe; PDBj
PDBsum
structure summary
Ala_racemase_C
Identifiers
Symbol
Ala_racemase_C
Pfam
PF00842
InterPro
IPR011079
PROSITE
PDOC00332
SCOP2
1sft / SCOPe / SUPFAM
Available protein structures:
Pfam
structures / ECOD
PDB
RCSB PDB; PDBe; PDBj
PDBsum
structure summary
In enzymology, an alanine racemase (EC 5.1.1.1) is an enzyme that catalyzes the chemical reaction
L-alanine D-alanine
Hence, this enzyme has one substrate, L-alanine, and one product, D-alanine.
This enzyme belongs to the family of isomerases, specifically those racemases and epimerases acting on amino acids and derivatives. The systematic name of this enzyme class is alanine racemase. This enzyme is also called L-alanine racemase. This enzyme participates in alanine and aspartate metabolism and D-alanine metabolism. It employs one cofactor, pyridoxal phosphate. At least two compounds, 3-Fluoro-D-alanine and D-Cycloserine are known to inhibit this enzyme.
The D-alanine produced by alanine racemase is used for peptidoglycan biosynthesis. Peptidoglycan is found in the cell walls of all bacteria, including many which are harmful to humans. The enzyme is absent in higher eukaryotes but found everywhere in prokaryotes, making alanine racemase a great target for antimicrobial drug development.[1] Alanine racemase can be found in some invertebrates.[2]
Bacteria can have one (alr gene) or two alanine racemase genes. Bacterial species with two genes for alanine racemase have one that is continually expressed and one that is inducible, which makes it difficult to target both genes for drug studies. However, knockout studies have shown that without the alr gene being expressed, the bacteria would need an external source of D-alanine in order to survive. Therefore, the alr gene is a feasible target for antimicrobial drugs.[1]
Alanine racemase is the only known protein, as of 2002, to contain a left-handed α-helix of 5 amino acids, the longest left-handed α-helix found up until at that point.[3]
^ abMilligan Daniel L.; et al. (2007). "The Alanine Racemase of Mycobacterium smegmatis Is Essential for Growth in the Absence of D-Alanine". Journal of Bacteriology. 189 (22): 8381–8386. doi:10.1128/jb.01201-07. PMC 2168708. PMID 17827284.
^Abe, H; Yoshikawa, N; Sarower, M. G.; Okada, S (2005). "Physiological function and metabolism of free D-alanine in aquatic animals". Biological & Pharmaceutical Bulletin. 28 (9): 1571–7. doi:10.1248/bpb.28.1571. PMID 16141518.
^Hovmöller, Sven; Zhou, Tuping; Ohlson, Tomas (May 2002). "Conformations of amino acids in proteins". Acta Crystallographica. Section D, Biological Crystallography. 58 (Pt 5): 768–776. doi:10.1107/s0907444902003359. ISSN 0907-4449. PMID 11976487.
enzymology, an alanineracemase (EC 5.1.1.1) is an enzyme that catalyzes the chemical reaction L-alanine ⇌ {\displaystyle \rightleftharpoons } D-alanine Hence...
aspartate 4-decarboxylase. Fermentation routes to L-alanine are complicated by alanineracemase. Racemic alanine can be prepared by the condensation of acetaldehyde...
aminotransferase family Fold Type II — tryptophan synthase family Fold Type III — alanineracemase family (TIM-barrel) Fold Type IV — D-amino acid aminotransferase family...
the action of other enzymes. The racemization of L-Ala to D-Ala by alanineracemase is pyridoxal phosphate-dependent. The formation of butenyl-methyl-L-threonine...
Epimerases and racemases are isomerase enzymes that catalyze the inversion of stereochemistry in biological molecules. Racemases catalyze the stereochemical...
determined that aspartate racemase also racemizes L-alanine around half as quickly as it does L-aspartate, but does not show racemase activity in the presence...
analogue of D-alanine, cycloserine acts against two crucial enzymes important in the cytosolic stages of peptidoglycan synthesis: alanineracemase (Alr) and...
and one of them is alanineracemase (alr). This enzyme is significant because it is found in D-alanine—D-alanine ligase and alanine/Aspartate metabolism...
to a radially splayed lobulated structure. The expression levels of alanineracemase affects the level of cyclosporine production by T. inflatum. Ciclosporin...
category (EC 5.1) includes (racemases) and epimerases). These isomerases invert stereochemistry at the target chiral carbon. Racemases act upon molecules with...
proteins. Seven proteins have been identified in washed exosporium: alanineracemase, inosine hydrolase, ExsF, CotY, ExsY, CotB, and a novel protein, ExsK...
and PBP1 are missing: alr encodes an enzyme L-alanineracemase, which converts L-alanine to D-alanine in the first step of peptidoglycan synthesis pathway;...
through protein synthesis. M. maripaludis uses alanineracemase and alanine permease for alanine uptake. A racemase enzyme is used to convert the inversion of...
protein L11 methyltransferase, iron-sulphur cluster-binding protein and alanineracemase, which in most cases are exclusively shared by either all or most members...
ornithine decarboxylase. DAPDC is a PLP-dependent enzyme belonging to the alanineracemase family. This enzyme is generally dimeric with each monomer containing...
Alanine World Hypothesis postulates that the evolution of the genetic code (the so-called GC phase) started with only four basic amino acids: alanine...
amine group to a different keto acid to create a new amino acid. Serine racemase which synthesizes the neuromodulator D-serine from its enantiomer is a...
biosynthesis.[citation needed] D-Serine, synthesized in neurons by serine racemase from L-serine (its enantiomer), serves as a neuromodulator by coactivating...
the bacteria (which produce it from the l form with the enzyme glutamate racemase) and the liver of mammals. Although they occur naturally in many foods...
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