L-xylulose reductase

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L-xylulose reductase
1wnt.jpg
L-Xylulose reductase tetramer, Human
Identifiers
EC number 1.1.1.10
Databases
IntEnz IntEnz view
BRENDA BRENDA entry
ExPASy NiceZyme view
KEGG KEGG entry
MetaCyc metabolic pathway
PRIAM profile
PDB structures RCSB PDB PDBe PDBsum
dicarbonyl/L-xylulose reductase
Human xylulose reductase holoenzyme.png
Identifiers
Symbol DCXR
Entrez 51181
HUGO 18985
OMIM 608347
RefSeq NM_016286
UniProt Q7Z4W1
Other data
EC number 1.1.1.10
Locus Chr. 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[edit]

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[edit]

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+ 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[edit]

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[edit]

  1. ^ Nakagawa J, Ishikura S, Asami J, Isaji T, Usami N, Hara A, Sakurai T, Tsuritani K, Oda K, Takahashi M, Yoshimoto M, Otsuka N, Kitamura K (2002). "Molecular characterization of mammalian dicarbonyl/L-xylulose reductase and its localization in kidney". J. Biol. Chem. 277 (20): 17883–91. doi:10.1074/jbc.M110703200. PMID 11882650. 
  2. ^ Zhao HT, Endo S, Ishikura S, Chung R, Hogg PJ, Hara A, El-Kabbani O (2009). "Structure/function analysis of a critical disulfide bond in the active site of L-xylulose reductase". Cell. Mol. Life Sci. 66 (9): 1570–9. doi:10.1007/s00018-009-9065-y. PMID 19337691. 
  3. ^ Cho-Vega JH, Tsavachidis S, Do KA, Nakagawa J, Medeiros LJ, McDonnell TJ (2007). "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. doi:10.1158/1055-9965.EPI-07-0684. PMID 18086765. 

External links[edit]