Functional Characterization of Endo- and Exo-Hydrolase Genes in Arabinan Degradation Gene Cluster of <i>Bifidobacterium longum</i> subsp. <i>suis</i>
Bifidobacteria are probiotic microorganisms commonly found in the gastrointestinal tract, some of which are known to utilize linear arabino-oligosaccharides (AOS) as prebiotic carbohydrates. In general, the synergistic actions of exo-type α-<span style="font-variant: small-caps;">l&l...
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2024-03-01
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| Series: | International Journal of Molecular Sciences |
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| author | Yewon Kang Chang-Yun Choi Jihun Kang Ye-Rin Ju Hye Bin Kim Nam Soo Han Tae-Jip Kim |
| author_facet | Yewon Kang Chang-Yun Choi Jihun Kang Ye-Rin Ju Hye Bin Kim Nam Soo Han Tae-Jip Kim |
| author_sort | Yewon Kang |
| collection | DOAJ |
| description | Bifidobacteria are probiotic microorganisms commonly found in the gastrointestinal tract, some of which are known to utilize linear arabino-oligosaccharides (AOS) as prebiotic carbohydrates. In general, the synergistic actions of exo-type α-<span style="font-variant: small-caps;">l</span>-arabinofuranosidases (ABFs) and endo-α-1,5-<span style="font-variant: small-caps;">l</span>-arabinanases (ABNs) are required for efficient arabinan degradation. In this study, the putative gene cluster for arabinan degradation was discovered in the genome of <i>Bifidobacterium longum</i> subsp. <i>suis</i>. It consists of a variety of genes encoding exo- and endo-hydrolases, sugar-binding proteins, ABC-binding cassettes, and transcriptional regulators. Among them, two endo-ABNs GH43 (BflsABN43A and BflsABN43B), two exo-ABFs GH43 (BflsABF43A and BflsABF43B), and an exo-ABF GH51 (BflsABF51) were predicted to be the key hydrolases for arabinan degradation. These hydrolase genes were functionally expressed in <i>Escherichia coli</i>, and their enzymatic properties were characterized. Their synergism in arabinan degradation has been proposed from the detailed modes of action. Extracellular endo-BflsABN43A hydrolyzes sugar beet and debranched arabinans into the short-chain branched and linear AOS. Intracellularly, AOS can be further degraded into <span style="font-variant: small-caps;">l</span>-arabinose via the cooperative actions of endo-BflsABN43B, exo-BflsABF43A with debranching activity, α-1,5-linkage-specific exo-BflsABF43B, and exo-BflsABF51 with dual activities. The resulting <span style="font-variant: small-caps;">l</span>-arabinose is expected to be metabolized into energy through the pentose phosphate pathway by three enzymes expressed from the <i>ara</i> operon of bifidobacteria. It is anticipated that uncovering arabinan utilization gene clusters and their detailed functions in the genomes of diverse microorganisms will facilitate the development of customized synbiotics. |
| first_indexed | 2024-04-24T18:12:10Z |
| format | Article |
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| issn | 1661-6596 1422-0067 |
| language | English |
| last_indexed | 2024-04-24T18:12:10Z |
| publishDate | 2024-03-01 |
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| spelling | doaj.art-399047fab7b0474d8b8fd86c27550f7c2024-03-27T13:45:14ZengMDPI AGInternational Journal of Molecular Sciences1661-65961422-00672024-03-01256317510.3390/ijms25063175Functional Characterization of Endo- and Exo-Hydrolase Genes in Arabinan Degradation Gene Cluster of <i>Bifidobacterium longum</i> subsp. <i>suis</i>Yewon Kang0Chang-Yun Choi1Jihun Kang2Ye-Rin Ju3Hye Bin Kim4Nam Soo Han5Tae-Jip Kim6Division of Animal, Horticultural and Food Sciences, Graduate School of Chungbuk National University, Cheongju 28644, Republic of KoreaDivision of Animal, Horticultural and Food Sciences, Graduate School of Chungbuk National University, Cheongju 28644, Republic of KoreaDivision of Animal, Horticultural and Food Sciences, Graduate School of Chungbuk National University, Cheongju 28644, Republic of KoreaDivision of Animal, Horticultural and Food Sciences, Graduate School of Chungbuk National University, Cheongju 28644, Republic of KoreaDivision of Animal, Horticultural and Food Sciences, Graduate School of Chungbuk National University, Cheongju 28644, Republic of KoreaDivision of Animal, Horticultural and Food Sciences, Graduate School of Chungbuk National University, Cheongju 28644, Republic of KoreaDivision of Animal, Horticultural and Food Sciences, Graduate School of Chungbuk National University, Cheongju 28644, Republic of KoreaBifidobacteria are probiotic microorganisms commonly found in the gastrointestinal tract, some of which are known to utilize linear arabino-oligosaccharides (AOS) as prebiotic carbohydrates. In general, the synergistic actions of exo-type α-<span style="font-variant: small-caps;">l</span>-arabinofuranosidases (ABFs) and endo-α-1,5-<span style="font-variant: small-caps;">l</span>-arabinanases (ABNs) are required for efficient arabinan degradation. In this study, the putative gene cluster for arabinan degradation was discovered in the genome of <i>Bifidobacterium longum</i> subsp. <i>suis</i>. It consists of a variety of genes encoding exo- and endo-hydrolases, sugar-binding proteins, ABC-binding cassettes, and transcriptional regulators. Among them, two endo-ABNs GH43 (BflsABN43A and BflsABN43B), two exo-ABFs GH43 (BflsABF43A and BflsABF43B), and an exo-ABF GH51 (BflsABF51) were predicted to be the key hydrolases for arabinan degradation. These hydrolase genes were functionally expressed in <i>Escherichia coli</i>, and their enzymatic properties were characterized. Their synergism in arabinan degradation has been proposed from the detailed modes of action. Extracellular endo-BflsABN43A hydrolyzes sugar beet and debranched arabinans into the short-chain branched and linear AOS. Intracellularly, AOS can be further degraded into <span style="font-variant: small-caps;">l</span>-arabinose via the cooperative actions of endo-BflsABN43B, exo-BflsABF43A with debranching activity, α-1,5-linkage-specific exo-BflsABF43B, and exo-BflsABF51 with dual activities. The resulting <span style="font-variant: small-caps;">l</span>-arabinose is expected to be metabolized into energy through the pentose phosphate pathway by three enzymes expressed from the <i>ara</i> operon of bifidobacteria. It is anticipated that uncovering arabinan utilization gene clusters and their detailed functions in the genomes of diverse microorganisms will facilitate the development of customized synbiotics.https://www.mdpi.com/1422-0067/25/6/3175<i>Bifidobacterium longum</i> subsp. <i>suis</i>arabinan degradation gene clusterendo-α-(1,5)-<span style="font-variant: small-caps">l</span>-arabinanases (ABNs)exo-α-<span style="font-variant: small-caps">l</span>-arabinofuranosidases (ABFs)hydrolytic modes of action |
| spellingShingle | Yewon Kang Chang-Yun Choi Jihun Kang Ye-Rin Ju Hye Bin Kim Nam Soo Han Tae-Jip Kim Functional Characterization of Endo- and Exo-Hydrolase Genes in Arabinan Degradation Gene Cluster of <i>Bifidobacterium longum</i> subsp. <i>suis</i> International Journal of Molecular Sciences <i>Bifidobacterium longum</i> subsp. <i>suis</i> arabinan degradation gene cluster endo-α-(1,5)-<span style="font-variant: small-caps">l</span>-arabinanases (ABNs) exo-α-<span style="font-variant: small-caps">l</span>-arabinofuranosidases (ABFs) hydrolytic modes of action |
| title | Functional Characterization of Endo- and Exo-Hydrolase Genes in Arabinan Degradation Gene Cluster of <i>Bifidobacterium longum</i> subsp. <i>suis</i> |
| title_full | Functional Characterization of Endo- and Exo-Hydrolase Genes in Arabinan Degradation Gene Cluster of <i>Bifidobacterium longum</i> subsp. <i>suis</i> |
| title_fullStr | Functional Characterization of Endo- and Exo-Hydrolase Genes in Arabinan Degradation Gene Cluster of <i>Bifidobacterium longum</i> subsp. <i>suis</i> |
| title_full_unstemmed | Functional Characterization of Endo- and Exo-Hydrolase Genes in Arabinan Degradation Gene Cluster of <i>Bifidobacterium longum</i> subsp. <i>suis</i> |
| title_short | Functional Characterization of Endo- and Exo-Hydrolase Genes in Arabinan Degradation Gene Cluster of <i>Bifidobacterium longum</i> subsp. <i>suis</i> |
| title_sort | functional characterization of endo and exo hydrolase genes in arabinan degradation gene cluster of i bifidobacterium longum i subsp i suis i |
| topic | <i>Bifidobacterium longum</i> subsp. <i>suis</i> arabinan degradation gene cluster endo-α-(1,5)-<span style="font-variant: small-caps">l</span>-arabinanases (ABNs) exo-α-<span style="font-variant: small-caps">l</span>-arabinofuranosidases (ABFs) hydrolytic modes of action |
| url | https://www.mdpi.com/1422-0067/25/6/3175 |
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