MetaCyc Enzyme: 2-keto-3-deoxyxylonate dehydratase

Gene: HVO_B0027 Accession Number: G-12646 (MetaCyc)

Species: Haloferax volcanii

The subunit structure of this enzyme has not been reported.

This dehydratase was shown to be essential for α-D-xylopyranose (D-xylose) degradation in the halophilic archaeon Haloferax volcanii. Orthologs with 63% and 56% amino acid sequence identity were found in Haloarcula marismortui and Halorubrum lacusprofundi, respectively. A characterized ortholog in the archaeon Sulfolobus solfataricus was 40% identical and a putative ortholog in the bacterium Caulobacter crescentus CB15 was 18% identical. These enzymes belong to the fumaroylacetoacetate hydrolase superfamily [Johnsen09].

An in-frame deletion mutant of the gene encoding this enzyme resulted in inability to grow on α-D-xylopyranose, while growth on D-glucose was unaffected [Johnsen09].

DNA microarray analyses showed that the transcription of this gene was highly up-regulated by growth on α-D-xylopyranose. It formed part of a transcription unit with HVO_B0028 encoding D-xylose dehydrogenase [Johnsen09].

The genome of this organism is composed of a main chromosome of 2.848 Mb, three smaller chromosomes (pHV4, pHV3 and pHV1) and a plasmid pHV2 [Hartman10]. This gene is located on pHV3.

Map Position: [29,918 -> 30,787]

Molecular Weight of Polypeptide: 31.862 kD (from nucleotide sequence)

Unification Links: Entrez-gene:8919100 , Protein Model Portal:D4GP28 , UniProt:D4GP28

Relationship Links: InterPro:IN-FAMILY:IPR002529 , InterPro:IN-FAMILY:IPR011234 , Pfam:IN-FAMILY:PF01557

Gene-Reaction Schematic: ?

Gene-Reaction Schematic

Created 18-Mar-2011 by Fulcher CA , SRI International

Enzymatic reaction of: 2-keto-3-deoxyxylonate dehydratase

EC Number:

2-dehydro-3-deoxy-D-arabinonate <=> 2,5-dioxopentanoate + H2O

The reaction direction shown, that is, A + B ↔ C + D versus C + D ↔ A + B, is in accordance with the Enzyme Commission system.

The reaction is favored in the direction shown.

In Pathways: superpathway of pentose and pentitol degradation , xylose degradation III


Hartman10: Hartman AL, Norais C, Badger JH, Delmas S, Haldenby S, Madupu R, Robinson J, Khouri H, Ren Q, Lowe TM, Maupin-Furlow J, Pohlschroder M, Daniels C, Pfeiffer F, Allers T, Eisen JA (2010). "The complete genome sequence of Haloferax volcanii DS2, a model archaeon." PLoS One 5(3);e9605. PMID: 20333302

Johnsen09: Johnsen U, Dambeck M, Zaiss H, Fuhrer T, Soppa J, Sauer U, Schonheit P (2009). "D-xylose degradation pathway in the halophilic archaeon Haloferax volcanii." J Biol Chem 284(40);27290-303. PMID: 19584053

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Please cite the following article in publications resulting from the use of MetaCyc: Caspi et al, Nucleic Acids Research 42:D459-D471 2014
Page generated by SRI International Pathway Tools version 19.0 on Tue Jul 28, 2015, BIOCYC14A.