Alanine racemase

alanine racemase
The 1.45Å a crystal structure of alanine racemase from Pseudomonas aeruginosa, PDB 1rcq
Identifiers
EC number	5.1.1.1
CAS number	9024-06-0
Databases
IntEnz	IntEnz view
BRENDA	BRENDA entry
ExPASy	NiceZyme view
KEGG	KEGG entry
MetaCyc	metabolic pathway
PRIAM	profile
PDB structures	RCSB PDB PDBe PDBsum
Gene Ontology	AmiGO / EGO
Search PMC articles PubMed articles

Ala_racemase_N

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
SCOP	1sft
SUPERFAMILY	1sft
Available protein structures: Pfam structures PDB RCSB PDB; PDBe 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.

Structural studies

The structure of alanine racemase from Bacillus stearothermophilus (Geobacillus stearothermophilus) was determined by X-ray crystallography to a resolution of 1.9 A.^[1] The alanine racemase monomer is composed of two domains, an eight-stranded alpha/beta barrel at the N terminus, and a C-terminal domain essentially composed of beta-strand. The N-terminal domain is also found in the PROSC (proline synthetase co-transcribed bacterial homolog) family of proteins, which are not known to have alanine racemase activity. The pyridoxal 5'-phosphate (PLP) cofactor lies in and above the mouth of the alpha/beta barrel and is covalently linked via an aldimine linkage to a lysine residue, which is at the C terminus of the first beta-strand of the alpha/beta barrel.

References

Further reading

• MARR AG, WILSON PW (1954). "The alanine racemase of Brucella abortus". Arch. Biochem. Biophys. 49 (2): 424–33. doi:10.1016/0003-9861(54)90211-8. PMID 13159289. 
• Wood WA (1955). "Amino acid racemases". Methods Enzymol. 2: 212–217. doi:10.1016/S0076-6879(55)02189-7. 
• WOOD WA, GUNSALUS IC (1951). "D-Alanine formation; a racemase in Streptococcus faecalis". J. Biol. Chem. 190 (1): 403–16. PMID 14841188. 

This article incorporates text from the public domain Pfam and InterPro IPR011079