Biology:L-xylulose reductase

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Short description: Enzyme
L-xylulose reductase
1wnt.jpg
L-Xylulose reductase tetramer, Human
Identifiers
EC number1.1.1.10
Databases
IntEnzIntEnz view
BRENDABRENDA entry
ExPASyNiceZyme view
KEGGKEGG entry
MetaCycmetabolic pathway
PRIAMprofile
PDB structuresRCSB PDB PDBe PDBsum
dicarbonyl/L-xylulose reductase
Human xylulose reductase holoenzyme.png
Identifiers
SymbolDCXR
NCBI gene51181
HGNC18985
OMIM608347
RefSeqNM_016286
UniProtQ7Z4W1
Other data
EC number1.1.1.10
LocusChr. 17 q25.3

Dicarbonyl/L-xylulose reductase, also known as carbonyl reductase II, is an enzyme that in human is encoded by the DCXR gene located on chromosome 17.

Structure

The DCXR gene encodes a membrane protein that is approximately 34 kDa in size and composed of 224 amino acids. The protein is highly expressed in the kidney and localizes to the cytoplasmic membrane.[1]

Function

DCSR catalyzes the reduction of several L-xylylose as well as a number of pentoses, tetroses, trioses, alpha-dicarbonyl compounds. The enzyme is involved in carbohydrate metabolism, glucose metabolism, the uronate cycle and may play a role in the water absorption and cellular osmoregulation in the proximal renal tubules by producing xylitol.[2]

In enzymology, an L-xylulose reductase (EC 1.1.1.10) is an enzyme that catalyzes the chemical reaction

xylitol + NADP+ [math]\displaystyle{ \rightleftharpoons }[/math] L-xylulose + NADPH + H+

Thus, the two substrates of this enzyme are xylitol and NADP+, whereas its 3 products are L-xylulose, NADPH, and H+.

This enzyme belongs to the superfamily of short-chain oxidoreductases, specifically those acting on the CH-OH group of donor with NAD+ or NADP+ as acceptor. The systematic name of this enzyme class is xylitol:NADP+ 2-oxidoreductase (L-xylulose-forming).

Clinical significance

A deficiency is responsible for pentosuria. The insufficiency of L-xylulose reductase activity causes an inborn error of metabolism disease characterized by excessive urinary excretion of L-xylulose.

Over-expression and ectopic expression of the protein may be associated with prostate adenocarcinoma.[3]

References

  1. "Molecular characterization of mammalian dicarbonyl/L-xylulose reductase and its localization in kidney". J. Biol. Chem. 277 (20): 17883–91. 2002. doi:10.1074/jbc.M110703200. PMID 11882650. 
  2. "Structure/function analysis of a critical disulfide bond in the active site of L-xylulose reductase". Cell. Mol. Life Sci. 66 (9): 1570–9. 2009. doi:10.1007/s00018-009-9065-y. PMID 19337691. 
  3. "Dicarbonyl/L-xylulose reductase: a potential biomarker identified by laser-capture microdissection-micro serial analysis of gene expression of human prostate adenocarcinoma". Cancer Epidemiol. Biomarkers Prev. 16 (12): 2615–22. 2007. doi:10.1158/1055-9965.EPI-07-0684. PMID 18086765. 

External links