Open AccessPentose degradation in archaea: Halorhabdus species degrade D-xylose, L-arabinose and D-ribose via bacterial-type pathways
Author(s) -
Jan-Moritz Sutter,
Ulrike Johnsen,
Andreas Reinhardt,
Peter Schönheit
Publication year - 2020
Publication title -
extremophiles
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.767
H-Index - 83
eISSN - 1433-4909
pISSN - 1431-0651
DOI - 10.1007/s00792-020-01192-y
Subject(s) - biochemistry , pentose phosphate pathway , haloferax volcanii , isomerase , pentose , ribose , biology , xylose , archaea , transaldolase , arabinose , xylose metabolism , metabolic pathway , enzyme , glycolysis , fermentation , gene
The degradation of the pentoses D-xylose, L-arabinose and D-ribose in the domain of archaea, in Haloferax volcanii and in Haloarcula and Sulfolobus species, has been shown to proceed via oxidative pathways to generate α-ketoglutarate. Here, we report that the haloarchaeal Halorhabdus species utilize the bacterial-type non-oxidative degradation pathways for pentoses generating xylulose-5-phosphate. The genes of these pathways are each clustered and were constitutively expressed. Selected enzymes involved in D-xylose degradation, xylose isomerase and xylulokinase, and those involved in L-arabinose degradation, arabinose isomerase and ribulokinase, were characterized. Further, D-ribose degradation in Halorhabdus species involves ribokinase, ribose-5-phosphate isomerase and D-ribulose-5-phosphate-3-epimerase. Ribokinase of Halorhabdus tiamatea and ribose-5-phosphate isomerase of Halorhabdus utahensis were characterized. This is the first report of pentose degradation via the bacterial-type pathways in archaea, in Halorhabdus species that likely acquired these pathways from bacteria. The utilization of bacterial-type pathways of pentose degradation rather than the archaeal oxidative pathways generating α-ketoglutarate might be explained by an incomplete gluconeogenesis in Halorhabdus species preventing the utilization of α-ketoglutarate in the anabolism.