Identification and characterization of an archaeal kojibiose catabolic pathway in the hyperthermophilic Pyrococcus sp. strain ST04

J Bacteriol. 2014 Mar;196(5):1122-31. doi: 10.1128/JB.01222-13. Epub 2014 Jan 3.


A unique gene cluster responsible for kojibiose utilization was identified in the genome of Pyrococcus sp. strain ST04. The proteins it encodes hydrolyze kojibiose, a disaccharide product of glucose caramelization, and form glucose-6-phosphate (G6P) in two steps. Heterologous expression of the kojibiose-related enzymes in Escherichia coli revealed that two genes, Py04_1502 and Py04_1503, encode kojibiose phosphorylase (designated PsKP, for Pyrococcus sp. strain ST04 kojibiose phosphorylase) and β-phosphoglucomutase (PsPGM), respectively. Enzymatic assays show that PsKP hydrolyzes kojibiose to glucose and β-glucose-1-phosphate (β-G1P). The Km values for kojibiose and phosphate were determined to be 2.53 ± 0.21 mM and 1.34 ± 0.04 mM, respectively. PsPGM then converts β-G1P into G6P in the presence of 6 mM MgCl2. Conversion activity from β-G1P to G6P was 46.81 ± 3.66 U/mg, and reverse conversion activity from G6P to β-G1P was 3.51 ± 0.13 U/mg. The proteins are highly thermostable, with optimal temperatures of 90°C for PsKP and 95°C for PsPGM. These results indicate that Pyrococcus sp. strain ST04 converts kojibiose into G6P, a substrate of the glycolytic pathway. This is the first report of a disaccharide utilization pathway via phosphorolysis in hyperthermophilic archaea.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Archaeal Proteins / genetics
  • Archaeal Proteins / metabolism*
  • Cloning, Molecular
  • Disaccharides / metabolism*
  • Gene Expression Regulation, Archaeal / physiology*
  • Molecular Sequence Data
  • Pyrococcus / genetics
  • Pyrococcus / metabolism*
  • Substrate Specificity


  • Archaeal Proteins
  • Disaccharides
  • kojibiose

Associated data

  • GENBANK/AAK04526
  • GENBANK/AAV43670
  • GENBANK/ABB51158
  • GENBANK/ABP66077
  • GENBANK/ABP66082
  • GENBANK/ABX41399
  • GENBANK/ABX42243
  • GENBANK/BAB97299
  • GENBANK/BAB97300
  • GENBANK/BAC20640
  • GENBANK/BAC54904
  • GENBANK/BAD97810
  • GENBANK/CAA11905
  • GENBANK/CAA58961
  • GENBANK/EAA66407