• 미생물학회지
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• 제42권1호
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• pp.67-72
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• 2006

클로닝된 Bacillus circulans ATCC21367 유래 cellulolytic xylanase 유전자(bglBC2)의 염기서열을 결정 분석하였다. 본 유전자는 1,224 bp의 407개 아미노산을 암호하는 open reading frame (ORF)으로 구성되어 있었으며 염기서열로부터 산출된 유전자의 분자량은 45 kDa으로 효소의 SDS-PAGE로부터 측정된 분자량과 일치하였다. ATG 개시 코돈의 9bp 위쪽에 Shine-Dalgarno (SD) 서열로 추정되는 5'-AAAGGAG-3' 서열이 확인되었고 그 상단에 promoter로 추정되는 -35 서열(TTTACA)과 -10 서열(TATACT)이 위치하고 있었으며, 이는 B. subtilis promoter consensus sequence와 유사하였다. 한편, 이 효소의 아미노산 서열은 이미 보고된 B. circulans KSM-N257의 alkaline $endo-\beta-1,4-glucanase$와는 97%, B. circulans WL-12의 $endo-\beta-1,3-1,4-glucanase$와는 75%, Bacillus sp. KSM-330의 $endo-\beta-1,4-glucanase$ (cellulase)와는 45%의 유사성을 나타내었다. 또한 bglBCS 염기서 열의 정보를 GenBank에 등록하였으며 등록번호는 Ar269256이다.

• 한국미생물·생명공학회지
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• 제41권3호
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• pp.263-271
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• 2013

균주 HX-1은 토양샘플로부터 분리된 자일라네이즈 생산 미생물로서 16S rRNA 유전자 염기서열 분석과 이를 이용한 phylogenetic tree 제작을 통하여 Paenibacillus 속의 한 종으로 동정되었다. 그러나 HX-1 균주가 계통발생적 연관관계가 높은 기존에 알려진 표준군주들과는 상당히 다른 생리적-생화학적 특성을 나타내는 사실로부터 HX-1이 신아종일 것으로 판단하고, Paenibacillus sp. HX-1으로 명명하였다. 균주 HX-1로부터의 자일라네이즈 생산을 증가시키는 배지조건을 탐색하여 최적화된 TNX 배지(1% bacto tryptone, 0.7% 자일란, 1% NaCl; pH 7.0)에서 약 7.4배에 달하는 자일라네이즈 생산량의 증가가 가능하였다. 균주 HX-1이 분비하는 자일라네이즈는 pH 7.0과 $45^{\circ}C$에서 최적의 효소활성을 나타냈으며, beechwood 자일란을 기질로 하는 효소반응으로부터 xylobiose를 최종산물로 생산하는 endo-${\beta}$-1,4-xylanase임을 확인하였다. 본 연구로부터 동정된 Paenibacillus sp. HX-1은 다양한 산업에 응용이 가능한 새로운 자일라네이즈를 제공할 수 있는 중요한 균으로 사료된다.

• BMB Reports
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• 제38권1호
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• pp.17-23
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• 2005

During the screening of xylanolytic enzymes from locally isolated fungi, one strain BCC14405, exhibited high enzyme activity with thermostability. This fugal strain was identified as Aspergillus cf. niger based on its morphological characteristics and internal transcribed spacer (ITS) sequences. An enzyme with xylanolytic activity from BCC14405 was later purified and characterized. It was found to have a molecular mass of ca. 21 kDa, an optimal pH of 5.0, and an optimal temperature of $55^{\circ}C$. When tested using xylan from birchwood, it showed $K_m$ and $V_{max}$ values of 8.9 mg/ml and 11,100 U/mg, respectively. The enzyme was inhibited by $CuSO_4$, EDTA, and by $FeSO_4$. The homology of the 20-residue N-terminal protein sequence showed that the enzyme was an endo-1,4-$\beta$-xylanase. The full-length gene encoding endo-1,4-$\beta$-xylanase from BCC14405 was obtained by PCR amplification of its cDNA. The gene contained an open reading frame of 678 bp, encoding a 225 amino acid protein, which was identical to the endo-1,4-$\^{a}$-xylanase B previously identified in A. niger.

• Journal of Microbiology and Biotechnology
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• 제19권8호
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• pp.823-828
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• 2009

An endo-${\beta}-1$,4-xylanase (${\beta}$-xylanase) from Trichoderma harzianum C4 was purified without cellulase activity by sequential chromatographies. The specific activity of the purified enzyme preparation was 430 units/mg protein on D-xylan. The complementary DNA (cDNA) encoding ${\beta}$-xylanase (xynII) was amplified by PCR and isolated from cDNA PCR libraries constructed from T. harzianum C4. The nucleotide sequence of the cDNA fragment contained an open reading frame of 663 bp that encodes 221 amino acids, of which the mature protein is homologous to several ${\beta}$-xylanases II. An intron of 63 bp was identified in the genomic DNA sequence of xynII. This gene was expressed in Saccharomyces cerevisiae strains under the control of adh1 (alcohol dehydrogenase I) and pgk1 (phosphoglycerate kinase I) promoters in 2 ${\mu}$-based plasmids, which could render recombinants able to secrete ${\beta}$-xylanase into the media.

• Mycobiology
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• 제39권2호
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• pp.121-124
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• 2011

The cDNA of endo-1,$4-{\beta}-xylanaseA$, isolated from Phaenerocheate chrysosporium was expressed in Pichia pastoris. Using either the intrinsic leader peptide of XynA or the ${\alpha}$-factor signal peptide of Saccharomyces cerevisiae, xylanaseA is efficiently secreted into the medium at maximum concentrations of 1,946 U/L and 2,496 U/L, respectively.

• 미생물학회지
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• 제32권4호
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• pp.306-314
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• 1994

Xylan과 관련 다당류 (xylotriose, xylotetraose, arabinoxylotriose)에 대한 Trichoderma koningii ATCC 26113에서 분리된 xylanase II의 작용양상은 xylanase II가 endo-enzyme이고 transxylosidation의 활성을 가지고 있다고 보여진다. Xylanase II에 의해 형성된 반응산물을 $^1HNMR$ 분광법으로 분석한 결과는 본 효소에 의해 얻어진 xylooligosaccharides의 가수분해산물은 모두가 ${\beta}$-1,4-xylosidic linkage만을 가지고 있는 것으로 판명되었다. 본 효소를 iodoacetamide로 화학적으로 변형시켰을 때 효소 mole당 cysteine 잔기가 두 개가 활성에 필요한 것으로 보여졌으며, N-bromosuccinimide 로 처리하였을 때는 활성부위에 tryptophan 잔기가 여덟 개 존재하는 것으로 판명되었다.

• Journal of Microbiology and Biotechnology
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• 제24권7호
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• pp.943-953
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• 2014

The XylH gene (1,167-bp) encoding a novel hemicellulase (41,584 Da) was identified from the genome of Microbacterium trichothecenolyticum HY-17, a gastrointestinal bacterium of Gryllotalpa orientalis. The enzyme consisted of a single catalytic domain, which is 74% identical to that of an endo-${\beta}$-1,4-xylanase (GH10) from Isoptericola variabilis 225. Unlike other endo-${\beta}$-1,4-xylanases from invertebrate-symbiotic bacteria, rXylH was an alkali-tolerant multifunctional enzyme possessing endo-${\beta}$-1,4-xylanase activity together with ${\beta}$-1,3/${\beta}$-1,4-glucanase activity, which exhibited its highest xylanolytic activity at pH 9.0 and 60oC, and was relatively stable within a broad pH range of 5.0-10.0. The susceptibilities of different xylosebased polysaccharides to the XylH were assessed to be as follows: oat spelts xylan > beechwood xylan > birchwood xylan > wheat arabinoxylan. rXylH was also able to readily cleave p-nitrophenyl (pNP) cellobioside and pNP-xylopyranoside, but did not hydrolyze other pNP-sugar derivatives, xylobiose, or hexose-based materials. Enzymatic hydrolysis of birchwood xylan resulted in the product composition of xylobiose (71.2%) and xylotriose (28.8%) as end products.

• Journal of the Korean Wood Science and Technology
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• 제46권6호
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• pp.670-680
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• 2018

Acanthophysium sp. KMF001, a wood rotting fungus, produces a strong crude enzyme complex that efficiently produces simple sugars from wood. The transcriptomic analysis of Acanthophysium sp. KMF001 identified 14 genes for putative glycoside hydrolases. Among them, isotig01043 was expressed heterogeneously in Escherichia coli BL21(DE3), and the expressed protein exhibited an endo-${\beta}$-1,4-xylanase activity which showed the optimum reaction at pH 5.0 and $30^{\circ}C$. The enzyme kinetic values of $K_m$ and $V_{max}$ were 25.92 mg/ml and $0.628{\mu}mole/mg/ml$, respectively. The enzymatic characteristics of the expressed xylanase showed a typical fungal xylanase. However, the bioinformatics analysis suggested that the protein encoded by isotig01043 was a novel xylanase based on a low identity when it was compared with the closest protein in the NCBI database and a similar protein domain with GH16_fungal_Lam16A_glucanase, which had not been earlier suggested as a xylanase.

• Journal of the Korean Wood Science and Technology
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• 제19권2호
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• pp.22-29
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• 1991

The endo-1,4-${\beta}$-xylanase was extracted and purified from the extracellular xylanolytic systems of Trichoderma viride. The crude enzyme was chromatographed with ion-exchange reins of DEAE Sepharose CL-6B, Sepharose, S-Sepharose CL-6B and the resulting xylanase was turned out to be a single protein as 20KD hy SDS-polyacrylamide gel electrophoresis. The xylooligomers were obtained from xylan by incubation with the purified xylanase up to 50%. The ${\beta}$-xylosidase lost its activity completely by incubation of crude enzyme for 24hr with buffer solution of pH 2.8 at $27^{\circ}C$. And also, the xylooligomers were obtained from xylan as a main product by incubation with the crude enzyme treated with acidic buffer.

• Journal of Microbiology and Biotechnology
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• 제19권3호
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• pp.277-285
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• 2009

The nucleotide sequence of the Paenibacillus curdlanolyticus B-6 xyn10A gene, encoding a xylanase Xyn10A, consists of 3,828 nucleotides encoding a protein of 1,276 amino acids with a predicted molecular mass of 142,726 Da. Sequence analysis indicated that Xyn10A is a multidomain enzyme comprising nine domains in the following order: three family 22 carbohydrate-binding modules (CBMs), a family 10 catalytic domain of glycosyl hydrolases (xylanase), a family 9 CBM, a glycine-rich region, and three surface layer homology (SLH) domains. Xyn10A was purified from a recombinant Escherichia coli by a single step of affinity purification on cellulose. It could effectively hydrolyze agricultural wastes and pure insoluble xylans, especially low substituted insoluble xylan. The hydrolysis products were a series of short-chain xylooligosaccharides, indicating that the purified enzyme was an endo-$\beta$-1,4-xylanase. Xyn10A bound to various insoluble polysaccharides including Avicel, $\alpha$-cellulose, insoluble birchwood and oat spelt xylans, chitin, and starches, and the cell wall fragments of P. curdlanolyticus B-6, indicating that both the CBM and the SLH domains are fully functioning in the Xyn10A. Removal of the CBMs from Xyn10A strongly reduced the ability of plant cell wall hydrolysis. These results suggested that the CBMs of Xyn10A play an important role in the hydrolysis of plant cell walls.