PMID- 27297879
OWN - NLM
STAT- MEDLINE
DCOM- 20170529
LR  - 20181113
IS  - 1098-5530 (Electronic)
IS  - 0021-9193 (Print)
IS  - 0021-9193 (Linking)
VI  - 198
IP  - 16
DP  - 2016 Aug 15
TI  - Key Enzymes of the Semiphosphorylative Entner-Doudoroff Pathway in the 
      Haloarchaeon Haloferax volcanii: Characterization of Glucose Dehydrogenase, 
      Gluconate Dehydratase, and 2-Keto-3-Deoxy-6-Phosphogluconate Aldolase.
PG  - 2251-62
LID - 10.1128/JB.00286-16 [doi]
AB  - The halophilic archaeon Haloferax volcanii has been proposed to degrade glucose 
      via the semiphosphorylative Entner-Doudoroff (spED) pathway. So far, the key 
      enzymes of this pathway, glucose dehydrogenase (GDH), gluconate dehydratase 
      (GAD), and 2-keto-3-deoxy-6-phosphogluconate (KDPG) aldolase (KDPGA), have not 
      been characterized, and their functional involvement in glucose degradation has 
      not been demonstrated. Here we report that the genes HVO_1083 and HVO_0950 encode 
      GDH and KDPGA, respectively. The recombinant enzymes show high specificity for 
      glucose and KDPG and did not convert the corresponding C4 epimers galactose and 
      2-keto-3-deoxy-6-phosphogalactonate at significant rates. Growth studies of 
      knockout mutants indicate the functional involvement of both GDH and KDPGA in 
      glucose degradation. GAD was purified from H. volcanii, and the encoding gene, 
      gad, was identified as HVO_1488. GAD catalyzed the specific dehydration of 
      gluconate and did not utilize galactonate at significant rates. A knockout mutant 
      of GAD lost the ability to grow on glucose, indicating the essential involvement 
      of GAD in glucose degradation. However, following a prolonged incubation period, 
      growth of the Deltagad mutant on glucose was recovered. Evidence is presented that 
      under these conditions, GAD was functionally replaced by xylonate dehydratase 
      (XAD), which uses both xylonate and gluconate as substrates. Together, the 
      characterization of key enzymes and analyses of the respective knockout mutants 
      present conclusive evidence for the in vivo operation of the spED pathway for 
      glucose degradation in H. volcanii IMPORTANCE: The work presented here describes 
      the identification and characterization of the key enzymes glucose dehydrogenase, 
      gluconate dehydratase, and 2-keto-3-deoxy-6-phosphogluconate aldolase and their 
      encoding genes of the proposed semiphosphorylative Entner-Doudoroff pathway in 
      the haloarchaeon Haloferax volcanii The functional involvement of the three 
      enzymes was proven by analyses of the corresponding knockout mutants. These 
      results provide evidence for the in vivo operation of the semiphosphorylative 
      Entner-Doudoroff pathway in haloarchaea and thus expand our understanding of the 
      unusual sugar degradation pathways in the domain Archaea.
CI  - Copyright (c) 2016, American Society for Microbiology. All Rights Reserved.
FAU - Sutter, Jan-Moritz
AU  - Sutter JM
AD  - Institut fur Allgemeine Mikrobiologie, Christian-Albrechts-Universitat Kiel, 
      Kiel, Germany.
FAU - Tastensen, Julia-Beate
AU  - Tastensen JB
AD  - Institut fur Allgemeine Mikrobiologie, Christian-Albrechts-Universitat Kiel, 
      Kiel, Germany.
FAU - Johnsen, Ulrike
AU  - Johnsen U
AD  - Institut fur Allgemeine Mikrobiologie, Christian-Albrechts-Universitat Kiel, 
      Kiel, Germany.
FAU - Soppa, Jorg
AU  - Soppa J
AD  - Institute for Molecular Biosciences, Goethe University Frankfurt, Frankfurt, 
      Germany.
FAU - Schonheit, Peter
AU  - Schonheit P
AD  - Institut fur Allgemeine Mikrobiologie, Christian-Albrechts-Universitat Kiel, 
      Kiel, Germany peter.schoenheit@ifam.uni-kiel.de.
LA  - eng
PT  - Journal Article
DEP - 20160728
PL  - United States
TA  - J Bacteriol
JT  - Journal of bacteriology
JID - 2985120R
RN  - 0 (Archaeal Proteins)
RN  - EC 1.1.1.47 (Glucose 1-Dehydrogenase)
RN  - EC 4.1.2.- (Aldehyde-Lyases)
RN  - EC 4.1.2.14 (phospho-2-keto-3-deoxy-gluconate aldolase)
RN  - EC 4.2.1.- (Hydro-Lyases)
RN  - EC 4.2.1.39 (gluconate dehydratase)
SB  - IM
MH  - Aldehyde-Lyases/genetics/*metabolism
MH  - Amino Acid Sequence
MH  - Archaeal Proteins/genetics/*metabolism
MH  - Gene Deletion
MH  - Gene Expression Regulation, Archaeal/*physiology
MH  - Gene Expression Regulation, Enzymologic/*physiology
MH  - Glucose 1-Dehydrogenase/genetics/*metabolism
MH  - Haloferax volcanii/*enzymology/genetics/metabolism
MH  - Hydro-Lyases/genetics/*metabolism
MH  - Phylogeny
PMC - PMC4966447
EDAT- 2016/06/15 06:00
MHDA- 2017/05/30 06:00
PMCR- 2017/02/15
CRDT- 2016/06/15 06:00
PHST- 2016/04/07 00:00 [received]
PHST- 2016/06/06 00:00 [accepted]
PHST- 2016/06/15 06:00 [entrez]
PHST- 2016/06/15 06:00 [pubmed]
PHST- 2017/05/30 06:00 [medline]
PHST- 2017/02/15 00:00 [pmc-release]
AID - JB.00286-16 [pii]
AID - 00286-16 [pii]
AID - 10.1128/JB.00286-16 [doi]
PST - epublish
SO  - J Bacteriol. 2016 Jul 28;198(16):2251-62. doi: 10.1128/JB.00286-16. Print 2016 
      Aug 15.