Alanine racemase

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alanine racemase
PDB 1rcq EBI.jpg
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
Ala_racemase_N
PDB 1rcq EBI.jpg
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
Ala_racemase_C
Identifiers
Symbol Ala_racemase_C
Pfam PF00842
InterPro IPR011079
PROSITE PDOC00332
SCOP 1sft
SUPERFAMILY 1sft

In enzymology, an alanine racemase (EC 5.1.1.1) is an enzyme that catalyzes the chemical reaction

L-alanine \rightleftharpoons 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[edit]

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[edit]

  1. ^ Shaw JP, Petsko GA, Ringe D (February 1997). "Determination of the structure of alanine racemase from Bacillus stearothermophilus at 1.9-A resolution". Biochemistry 36 (6): 1329–42. doi:10.1021/bi961856c. PMID 9063881. 

Further reading[edit]

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