High substrate specificity of 3,6-anhydro-l-galactose dehydrogenase indicates its essentiality in the agar catabolism of a marine bacterium

Sora Yu, In-Geol Choi, Eun Ju Yun, Kyoung Heon Kim

Research output: Contribution to journalArticle

3 Citations (Scopus)

Abstract

3,6-Anhydro-l-galactose (AHG) is a rare sugar found in red macroalgae. The key metabolic steps in AHG catabolism involve its oxidation into 3,6-anhydrogalactonate (AHGA), followed by cycloisomerization of AHGA into 2-keto-3-deoxy-galactonate. These steps were recently discovered in a marine bacterium Vibrio sp. strain EJY3. In this study, we characterized NAD(P)+-dependent AHG dehydrogenase (AHGD) involved in the first step of AHG catabolism. AHGD displayed high substrate specificity for AHG, but showed no catalytic activity toward other aldehyde sugars, including D-form of AHG, glucose, and galactose. This high substrate specificity of AHGD may be associated with the unique chemical structure of its substrate AHG. Unlike other common aldehyde sugars, AHG mainly exists in its hydrated form under aqueous conditions. Growth of EJY3 in presence of AHG, agar, and Gelidium amansii but glucose, as the sole carbon source resulted in a significant increase in the AHGD activity of cell-free EJY3 lysates. Amino acid sequence analysis revealed that AHGD is highly homologous to other aldehyde dehydrogenases from agar-degrading bacteria, suggestive of its key role in agar-related metabolism in marine bacteria utilizing red macroalgae. Therefore, AHGD may serve as an important enzyme involved in the bioconversion of red macroalgal biomass to value-added chemicals.

Original languageEnglish
JournalProcess Biochemistry
DOIs
Publication statusAccepted/In press - 2017

Fingerprint

galactose dehydrogenase
Substrate Specificity
Galactose
Agar
Bacteria
Substrates
Oxidoreductases
Aldehydes
Sugars
Seaweed
Glucose
Bioconversion
Metabolism
Aldehyde Dehydrogenase
Vibrio
Amino acids
Protein Sequence Analysis
Catalyst activity
Biomass
Enzymes

Keywords

  • 3,6-anhydro-l-galactose
  • 3,6-anhydro-l-galactose dehydrogenase
  • 3,6-anhydrogalactonate
  • Agar
  • Agarose
  • Red macroalgae

ASJC Scopus subject areas

  • Bioengineering
  • Biochemistry
  • Applied Microbiology and Biotechnology

Cite this

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title = "High substrate specificity of 3,6-anhydro-l-galactose dehydrogenase indicates its essentiality in the agar catabolism of a marine bacterium",
abstract = "3,6-Anhydro-l-galactose (AHG) is a rare sugar found in red macroalgae. The key metabolic steps in AHG catabolism involve its oxidation into 3,6-anhydrogalactonate (AHGA), followed by cycloisomerization of AHGA into 2-keto-3-deoxy-galactonate. These steps were recently discovered in a marine bacterium Vibrio sp. strain EJY3. In this study, we characterized NAD(P)+-dependent AHG dehydrogenase (AHGD) involved in the first step of AHG catabolism. AHGD displayed high substrate specificity for AHG, but showed no catalytic activity toward other aldehyde sugars, including D-form of AHG, glucose, and galactose. This high substrate specificity of AHGD may be associated with the unique chemical structure of its substrate AHG. Unlike other common aldehyde sugars, AHG mainly exists in its hydrated form under aqueous conditions. Growth of EJY3 in presence of AHG, agar, and Gelidium amansii but glucose, as the sole carbon source resulted in a significant increase in the AHGD activity of cell-free EJY3 lysates. Amino acid sequence analysis revealed that AHGD is highly homologous to other aldehyde dehydrogenases from agar-degrading bacteria, suggestive of its key role in agar-related metabolism in marine bacteria utilizing red macroalgae. Therefore, AHGD may serve as an important enzyme involved in the bioconversion of red macroalgal biomass to value-added chemicals.",
keywords = "3,6-anhydro-l-galactose, 3,6-anhydro-l-galactose dehydrogenase, 3,6-anhydrogalactonate, Agar, Agarose, Red macroalgae",
author = "Sora Yu and In-Geol Choi and Yun, {Eun Ju} and Kim, {Kyoung Heon}",
year = "2017",
doi = "10.1016/j.procbio.2017.09.016",
language = "English",
journal = "Process Biochemistry",
issn = "1359-5113",
publisher = "Elsevier BV",

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T1 - High substrate specificity of 3,6-anhydro-l-galactose dehydrogenase indicates its essentiality in the agar catabolism of a marine bacterium

AU - Yu, Sora

AU - Choi, In-Geol

AU - Yun, Eun Ju

AU - Kim, Kyoung Heon

PY - 2017

Y1 - 2017

N2 - 3,6-Anhydro-l-galactose (AHG) is a rare sugar found in red macroalgae. The key metabolic steps in AHG catabolism involve its oxidation into 3,6-anhydrogalactonate (AHGA), followed by cycloisomerization of AHGA into 2-keto-3-deoxy-galactonate. These steps were recently discovered in a marine bacterium Vibrio sp. strain EJY3. In this study, we characterized NAD(P)+-dependent AHG dehydrogenase (AHGD) involved in the first step of AHG catabolism. AHGD displayed high substrate specificity for AHG, but showed no catalytic activity toward other aldehyde sugars, including D-form of AHG, glucose, and galactose. This high substrate specificity of AHGD may be associated with the unique chemical structure of its substrate AHG. Unlike other common aldehyde sugars, AHG mainly exists in its hydrated form under aqueous conditions. Growth of EJY3 in presence of AHG, agar, and Gelidium amansii but glucose, as the sole carbon source resulted in a significant increase in the AHGD activity of cell-free EJY3 lysates. Amino acid sequence analysis revealed that AHGD is highly homologous to other aldehyde dehydrogenases from agar-degrading bacteria, suggestive of its key role in agar-related metabolism in marine bacteria utilizing red macroalgae. Therefore, AHGD may serve as an important enzyme involved in the bioconversion of red macroalgal biomass to value-added chemicals.

AB - 3,6-Anhydro-l-galactose (AHG) is a rare sugar found in red macroalgae. The key metabolic steps in AHG catabolism involve its oxidation into 3,6-anhydrogalactonate (AHGA), followed by cycloisomerization of AHGA into 2-keto-3-deoxy-galactonate. These steps were recently discovered in a marine bacterium Vibrio sp. strain EJY3. In this study, we characterized NAD(P)+-dependent AHG dehydrogenase (AHGD) involved in the first step of AHG catabolism. AHGD displayed high substrate specificity for AHG, but showed no catalytic activity toward other aldehyde sugars, including D-form of AHG, glucose, and galactose. This high substrate specificity of AHGD may be associated with the unique chemical structure of its substrate AHG. Unlike other common aldehyde sugars, AHG mainly exists in its hydrated form under aqueous conditions. Growth of EJY3 in presence of AHG, agar, and Gelidium amansii but glucose, as the sole carbon source resulted in a significant increase in the AHGD activity of cell-free EJY3 lysates. Amino acid sequence analysis revealed that AHGD is highly homologous to other aldehyde dehydrogenases from agar-degrading bacteria, suggestive of its key role in agar-related metabolism in marine bacteria utilizing red macroalgae. Therefore, AHGD may serve as an important enzyme involved in the bioconversion of red macroalgal biomass to value-added chemicals.

KW - 3,6-anhydro-l-galactose

KW - 3,6-anhydro-l-galactose dehydrogenase

KW - 3,6-anhydrogalactonate

KW - Agar

KW - Agarose

KW - Red macroalgae

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