Next Article in Journal
Profiling of the Molecular Weight and Structural Isomer Abundance of Macroalgae-Derived Phlorotannins
Next Article in Special Issue
Mechanistic Insight into the Elastin Degradation Process by the Metalloprotease Myroilysin from the Deep-Sea Bacterium Myroides profundi D25
Previous Article in Journal
Synthesis and Antiproliferative Activity of Thiazolyl-bis-pyrrolo[2,3-b]pyridines and Indolyl-thiazolyl-pyrrolo[2,3-c]pyridines, Nortopsentin Analogues
Previous Article in Special Issue
Characterization of an Alginate Lyase, FlAlyA, from Flavobacterium sp. Strain UMI-01 and Its Expression in Escherichia coli
Article Menu

Export Article

Open AccessArticle
Mar. Drugs 2015, 13(1), 493-508;

Identification of a 4-Deoxy-l-erythro-5-hexoseulose Uronic Acid Reductase, FlRed, in an Alginolytic Bacterium Flavobacterium sp. Strain UMI-01

Laboratory of Marine Biotechnology and Microbiology, Faculty of Fisheries Sciences, Hokkaido University, Hakodate, Hokkaido 041-8611, Japan
Author to whom correspondence should be addressed.
Academic Editor: Alejandro Mayer
Received: 12 November 2014 / Accepted: 4 January 2015 / Published: 16 January 2015
(This article belongs to the Special Issue Green Chemistry Approach to Marine Products)
Full-Text   |   PDF [1484 KB, uploaded 24 February 2015]   |  


In alginate-assimilating bacteria, alginate is depolymerized to unsaturated monosaccharide by the actions of endolytic and exolytic alginate lyases (EC and EC The monosaccharide is non-enzymatically converted to 4-deoxy-l-ery thro-5-hexoseulose uronic acid (DEH), then reduced to 2-keto-3-deoxy-d-gluconate (KDG) by a specific reductase, and metabolized through the Entner–Doudoroff pathway. Recently, the NADPH-dependent reductase A1-R that belongs to short-chain dehydrogenases/reductases (SDR) superfamily was identified as the DEH-reductase in Sphingomonas sp. A1. We have subsequently noticed that an SDR-like enzyme gene, flred, occurred in the genome of an alginolytic bacterium Flavobacterium sp. strain UMI-01. In the present study, we report on the deduced amino-acid sequence of flred and DEH-reducing activity of recombinant FlRed. The deduced amino-acid sequence of flred comprised 254 residues and showed 34% amino-acid identities to that of A1-R from Sphingomonas sp. A1 and 80%–88% to those of SDR-like enzymes from several alginolytic bacteria. Common sequence motifs of SDR-superfamily enzymes, e.g., the catalytic tetrad Asn-Lys-Tyr-Ser and the cofactor-binding sequence Thr-Gly-x-x-x-Gly-x-Gly in Rossmann fold, were completely conserved in FlRed. On the other hand, an Arg residue that determined the NADPH-specificity of Sphingomonas A1-R was replaced by Glu in FlRed. Thus, we investigated cofactor-preference of FlRed using a recombinant enzyme. As a result, the recombinant FlRed (recFlRed) was found to show high specificity to NADH. recFlRed exhibited practically no activity toward variety of aldehyde, ketone, keto ester, keto acid and aldose substrates except for DEH. On the basis of these results, we conclude that FlRed is the NADH-dependent DEH-specific SDR of Flavobacterium sp. strain UMI-01. View Full-Text
Keywords: alginate metabolism; Flavobacterium; alginolytic gene; DEH reductase; SDR; NADH alginate metabolism; Flavobacterium; alginolytic gene; DEH reductase; SDR; NADH

Figure 1

This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited (CC BY 4.0).

Share & Cite This Article

MDPI and ACS Style

Inoue, A.; Nishiyama, R.; Mochizuki, S.; Ojima, T. Identification of a 4-Deoxy-l-erythro-5-hexoseulose Uronic Acid Reductase, FlRed, in an Alginolytic Bacterium Flavobacterium sp. Strain UMI-01. Mar. Drugs 2015, 13, 493-508.

Show more citation formats Show less citations formats

Related Articles

Article Metrics

Article Access Statistics



[Return to top]
Mar. Drugs EISSN 1660-3397 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top