1
|
Karim KMR, Husaini A, Sing NN, Tasnim T, Mohd Sinang F, Hussain H, Hossain MA, Roslan H. Characterization and expression in Pichia pastoris of a raw starch degrading glucoamylase (GA2) derived from Aspergillus flavus NSH9. Protein Expr Purif 2019; 164:105462. [PMID: 31351992 DOI: 10.1016/j.pep.2019.105462] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2019] [Revised: 06/19/2019] [Accepted: 07/24/2019] [Indexed: 11/25/2022]
Abstract
The Aspergillus flavus NSH9 gene, encoding a pH and thermostable glucoamylase with a starch binding domain (SBD), was expressed in Pichia pastoris to produce recombinant glucoamylase (rGA2). The full-length glucoamylase gene (2039 bp), and cDNA (1839 bp) encode a 612 amino acid protein most similar to glucoamylase from Aspergillus oryzae RIB40; the first 19 amino acids are presumed to be a signal peptide for secretion, and the SBD is at the C-terminal. The cDNA was successfully secreted by Pichia at 8.23 U mL-1, and the rGA2 was found to be: a 80 kDa monomer, stable from pH 3.0-9.0, with optimum catalytic activity at pH 5.0, active at temperatures up to 80°C (rGA2 retained 58% of its activity after 60 min of incubation at 70°C), and metal ions such as Na+, K+, Ca++ and Mg++ enhanced rGA2 enzyme activity. The starch degrading ability of rGA2 was also observed on raw sago starch and where prolonged incubation generated larger, deeper, holes on the starch granules, indicating rGA2 is an excellent candidate for industrial starch processing applications.
Collapse
Affiliation(s)
| | - Ahmad Husaini
- Faculty of Resource Science and Technology, Universiti Malaysia Sarawak, 94300, Kota, Samarahan, Sarawak, Malaysia.
| | - Ngieng Ngui Sing
- Faculty of Resource Science and Technology, Universiti Malaysia Sarawak, 94300, Kota, Samarahan, Sarawak, Malaysia
| | - Tasmia Tasnim
- Department of Nutrition and Food Engineering, Daffodil International University, Dhaka, 1207, Bangladesh
| | - Fazia Mohd Sinang
- Faculty of Resource Science and Technology, Universiti Malaysia Sarawak, 94300, Kota, Samarahan, Sarawak, Malaysia
| | - Hasnain Hussain
- Faculty of Resource Science and Technology, Universiti Malaysia Sarawak, 94300, Kota, Samarahan, Sarawak, Malaysia
| | - Md Anowar Hossain
- Department of Biochemistry and Molecular Biology, University of Rajshahi, Rajshahi, 6205, Bangladesh
| | - Hairul Roslan
- Faculty of Resource Science and Technology, Universiti Malaysia Sarawak, 94300, Kota, Samarahan, Sarawak, Malaysia
| |
Collapse
|
2
|
Lu H, Luo H, Shi P, Huang H, Meng K, Yang P, Yao B. A novel thermophilic endo-β-1,4-mannanase from Aspergillus nidulans XZ3: functional roles of carbohydrate-binding module and Thr/Ser-rich linker region. Appl Microbiol Biotechnol 2013; 98:2155-63. [DOI: 10.1007/s00253-013-5112-6] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2013] [Revised: 07/08/2013] [Accepted: 07/09/2013] [Indexed: 10/26/2022]
|
3
|
Kumar P, Satyanarayana T. Microbial glucoamylases: characteristics and applications. Crit Rev Biotechnol 2009; 29:225-55. [DOI: 10.1080/07388550903136076] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
|
4
|
Goto M. Protein O-glycosylation in fungi: diverse structures and multiple functions. Biosci Biotechnol Biochem 2007; 71:1415-27. [PMID: 17587671 DOI: 10.1271/bbb.70080] [Citation(s) in RCA: 135] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Protein glycosylation is essential for eukaryotic cells from yeasts to humans. When compared to N-glycosylation, O-glycosylation is variable in sugar components and the mode of linkages connecting the sugars. In fungi, secretory proteins are commonly mannosylated by protein O-mannosyltransferase (PMT) in the endoplasmic reticulum, and subsequently glycosylated by several glycosyltransferases in the Golgi apparatus to form glycoproteins with diverse O-glycan structures. Protein O-glycosylation has roles in modulating the function of secretory proteins by enhancing the stability and solubility of the proteins, by affording protection from protease degradation, and by acting as a sorting determinant in yeasts. In filamentous fungi, protein O-glycosylation contributes to proper maintenance of fungal morphology, hyphal development, and differentiation. This review describes recent studies of the structure and function of protein O-glycosylation in industrially and medically important fungi.
Collapse
Affiliation(s)
- Masatoshi Goto
- Department of Bioscience and Biotechnology, Faculty of Agriculture, Kyushu University, Japan.
| |
Collapse
|
5
|
Role of the linker region in the expression of Rhizopus oryzae glucoamylase. BMC BIOCHEMISTRY 2007; 8:9. [PMID: 17593302 PMCID: PMC1933424 DOI: 10.1186/1471-2091-8-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/09/2007] [Accepted: 06/25/2007] [Indexed: 11/10/2022]
Abstract
Background Rhizopus oryzae glucoamylase (RoGA) consists of three domains: an amino (N)-terminal raw starch-binding domain (SBD), a glycosylated linker domain, and a carboxy (C)-terminal catalytic domain. The 36-amino-acid linker region (residues 132–167) connects the two functional domains, but its structural and functional roles are unclear. Results To characterize the linker sequences of RoGA and its involvement in protein expression, a number of RoGA variants containing deletions and mutations were constructed and expressed in Saccharomyces cerevisiae. Deletion analyses demonstrate that the linker region, especially within residues 161 to 167, is required for protein expression. In addition, site-directed mutagenesis and deglycosylation studies reveal that the linker region of RoGA contains both N- and O-linked carbohydrate moieties, and the N-linked oligosaccharides play a major role in the formation of active enzyme. Although the linker segment itself appears to have no ordered secondary structural conformation, the flexible region indeed contributes to the stabilization of functional N- and C-terminal domains. Conclusion Our data provide direct evidence that the length, composition, and glycosylation of the interdomain linker play a central role in the structure and function of RoGA.
Collapse
|
6
|
Bhatti HN, Rashid MH, Asgher M, Nawaz R, Khalid AM, Perveen R. Chemical modification results in hyperactivation and thermostabilization ofFusarium solaniglucoamylase. Can J Microbiol 2007; 53:177-85. [PMID: 17496965 DOI: 10.1139/w06-094] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Chemical modification of carboxyl groups of glucoamylase from a mesophilic fungus, Fusarium solani , was carried out using ethylenediamine as nucleophile in the presence of water-soluble 1-ethyl-3(3-dimethylaminopropyl)carbodiimide. Modification brought about a dramatic enhancement of catalytic activity and thermal stability of glucoamylase. Temperature and pH optima of ethylenediamine-coupled glucoamylase (ECG) increased as compared with those of native enzyme. The specificity constant (kcat/Km) of native, ECG-2, ECG-11, and ECG-17 was 136, 173, 225, and 170, respectively, at 55 °C. The enthalpy of activation (ΔH*) and free energy of activation (ΔG*) for soluble starch hydrolysis were lower for the chemically modified forms. All of the modified forms werestable at higher temperatures and possessed high ΔG* against thermal unfolding. The effects of α-chymotrypsin and subtilisin on the modified forms were activating as compared with native. Moreover, denaturation of ECG-2, ECG-11, and ECG-17 in urea at 4 mol·L–1also showed an activation trend. A possible explanation for the thermal denaturation of native and increased thermal stability of ECG-2, ECG-11, and ECG-17 at higher temperatures is also discussed.
Collapse
Affiliation(s)
- Haq Nawaz Bhatti
- Department of Chemistry, University of Agriculture, Faisalabad, Pakistan 38040
| | | | | | | | | | | |
Collapse
|
7
|
Oka T, Sameshima Y, Koga T, Kim H, Goto M, Furukawa K. Protein O-mannosyltransferase A of Aspergillus awamori is involved in O-mannosylation of glucoamylase I. MICROBIOLOGY-SGM 2005; 151:3657-3667. [PMID: 16272387 DOI: 10.1099/mic.0.28088-0] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Industrially important extracellular enzymes from filamentous fungi are often O-mannosylated. The structure and function of the pmtA (AapmtA) gene encoding the protein O-D-mannosyltransferase of Aspergillus awamori were characterized. The AapmtA disruptant, designated AaPMTA, was constructed by homologous recombination. The strain AaPMTA exhibited fragile cell morphology with respect to hyphal extension, as well as swollen hyphae formation and conidia formation in potato dextrose medium. Moreover, the AapmtA disruptant showed increased sensitivity to high temperature and Congo red. Thus, the AaPmtA protein is involved in the formation of the normal cell wall. The strain AaPMTA could grow well in liquid synthetic medium and secrete glucoamylase I (GAI-AaPMTA) to a similar extent to the wild-type strain (GAI-WT). Matrix-assisted laser desorption ionization time-of-flight mass spectrometry analysis of the GAIs revealed that approximately 33 mannose moieties of GAI were absent in strain AaPMTA. This result indicates that the AaPmtA protein is responsible for the transfer of mannose to GAI. Structural analysis of the O-linked oligosaccharides of GAI also demonstrated that the AapmtA disruption resulted in a reduction of the amounts of O-linked oligosaccharides, such as D-mannose and alpha-1,2-mannotriose, in GAI-AaPMTA. However, the amount of alpha-1,2-mannobiose was comparable between GAI-WT and GAI-AaPMTA. The result suggests the presence of a compensatory mechanism in the synthetic pathway of O-mannosylation in A. awamori.
Collapse
Affiliation(s)
- Takuji Oka
- Department of Bioscience and Biotechnology, Faculty of Agriculture, Kyushu University, Hakozaki 6-10-1, Fukuoka 812-8581, Japan
| | - Yuka Sameshima
- Department of Bioscience and Biotechnology, Faculty of Agriculture, Kyushu University, Hakozaki 6-10-1, Fukuoka 812-8581, Japan
| | - Tomoko Koga
- Department of Bioscience and Biotechnology, Faculty of Agriculture, Kyushu University, Hakozaki 6-10-1, Fukuoka 812-8581, Japan
| | - Hoon Kim
- Department of Bioscience and Biotechnology, Faculty of Agriculture, Kyushu University, Hakozaki 6-10-1, Fukuoka 812-8581, Japan
| | - Masatoshi Goto
- Department of Bioscience and Biotechnology, Faculty of Agriculture, Kyushu University, Hakozaki 6-10-1, Fukuoka 812-8581, Japan
| | - Kensuke Furukawa
- Department of Bioscience and Biotechnology, Faculty of Agriculture, Kyushu University, Hakozaki 6-10-1, Fukuoka 812-8581, Japan
| |
Collapse
|
8
|
Goto M, Shinoda N, Oka T, Sameshima Y, Ekino K, Furukawa K. Thr/Ser-rich domain of Aspergillus glucoamylase is essential for secretion. Biosci Biotechnol Biochem 2005; 68:961-3. [PMID: 15118335 DOI: 10.1271/bbb.68.961] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The recombinant Aspergillus awamori strain carrying the mutant glucoamylase-encoding gene in which the entire Thr/Ser-rich Gp-I domain was deleted abolished secretion of mutant glucoamylase. The transcription of the Bip-encoding bipA was low in the wild type (wt) strain, but elevated in the recombinant strain under the condition of glaA expression. The results indicate that the Gp-I domain is vital for glucoamylase secretion.
Collapse
Affiliation(s)
- Masatoshi Goto
- Department of Bioscience and Biotechnology, Faculty of Agriculture, Kyushu University, Hakozaki, Fukuoka, Japan.
| | | | | | | | | | | |
Collapse
|
9
|
Rodríguez-Sanoja R, Ruiz B, Guyot JP, Sanchez S. Starch-binding domain affects catalysis in two Lactobacillus alpha-amylases. Appl Environ Microbiol 2005; 71:297-302. [PMID: 15640201 PMCID: PMC544272 DOI: 10.1128/aem.71.1.297-302.2005] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2004] [Accepted: 08/28/2004] [Indexed: 11/20/2022] Open
Abstract
A new starch-binding domain (SBD) was recently described in alpha-amylases from three lactobacilli (Lactobacillus amylovorus, Lactobacillus plantarum, and Lactobacillus manihotivorans). Usually, the SBD is formed by 100 amino acids, but the SBD sequences of the mentioned lactobacillus alpha-amylases consist of almost 500 amino acids that are organized in tandem repeats. The three lactobacillus amylase genes share more than 98% sequence identity. In spite of this identity, the SBD structures seem to be quite different. To investigate whether the observed differences in the SBDs have an effect on the hydrolytic capability of the enzymes, a kinetic study of L. amylovorus and L. plantarum amylases was developed, with both enzymes acting on several starch sources in granular and gelatinized forms. Results showed that the amylolytic capacities of these enzymes are quite different; the L. amylovorus alpha-amylase is, on average, 10 times more efficient than the L. plantarum enzyme in hydrolyzing all the tested polymeric starches, with only a minor difference in the adsorption capacities.
Collapse
Affiliation(s)
- R Rodríguez-Sanoja
- Departamento de Biología Molecular y Biotecnología, Instituto de Investigaciones Biomédicas, UNAM A. P. 70228, 04510 Mexico City, Mexico.
| | | | | | | |
Collapse
|
10
|
Nielsen BR, Lehmbeck J, Frandsen TP. Cloning, heterologous expression, and enzymatic characterization of a thermostable glucoamylase from Talaromyces emersonii. Protein Expr Purif 2002; 26:1-8. [PMID: 12356463 DOI: 10.1016/s1046-5928(02)00505-3] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The gene encoding a thermostable glucoamylase from Talaromyces emersonii was cloned and, subsequently, heterologously expressed in Aspergillus niger. This glucoamylase gene encodes a 618 amino acid long protein with a calculated molecular weight of 62,827Da. T. emersonii glucoamylase fall into glucoside hydrolase family 15, showing approximately 60% sequence similarity to glucoamylase from A. niger. The expressed enzyme shows high specific activity towards maltose, isomaltose, and maltoheptaose, having 3-6-fold elevated k(cat) compared to A. niger glucoamylase. T. emersonii glucoamylase showed significantly improved thermostability with a half life of 48h at 65 degrees C in 30% (w/v) glucose, compared to 10h for glucoamylase from A. niger. The ability of the glucoamylase to hydrolyse amylopectin at 65 degrees C is improved compared to A. niger glucoamylase, giving a significant higher final glucose yield at elevated temperatures. The increased thermal stability is thus reflected in the industrial performance, allowing T. emersonii glucoamylase to operate at a temperature higher than the A. niger enzyme.
Collapse
|
11
|
Hashimoto Y, Yamamoto T, Fujiwara S, Takagi M, Imanaka T. Extracellular synthesis, specific recognition, and intracellular degradation of cyclomaltodextrins by the hyperthermophilic archaeon Thermococcus sp. strain B1001. J Bacteriol 2001; 183:5050-7. [PMID: 11489857 PMCID: PMC95380 DOI: 10.1128/jb.183.17.5050-5057.2001] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2000] [Accepted: 06/04/2001] [Indexed: 11/20/2022] Open
Abstract
A unique extracellular and thermostable cyclomaltodextrin glucanotransferase (CGTase) from the hyperthermophilic archaeon Thermococcus sp. strain B1001 produces predominantly (>85%) alpha-cyclomaltodextrin (alpha-CD) from starch (Y. Tachibana, et al., Appl. Environ. Microbiol. 65:1991--1997, 1999). Nucleotide sequencing of the CGTase gene (cgtA) and its flanking region was performed, and a cluster of five genes was found, including a gene homolog encoding a cyclomaltodextrinase (CDase) involved in the degradation of CDs (cgtB), the gene encoding CGTase (cgtA), a gene homolog for a CD-binding protein (CBP) (cgtC), and a putative CBP-dependent ABC transporter involved in uptake of CDs (cgtDE). The CDase was expressed in Escherichia coli and purified. The optimum pH and temperature for CD hydrolysis were 5.5 and 95 degrees C, respectively. The molecular weight of the recombinant enzyme was estimated to be 79,000. The CDase hydrolyzed beta-CD most efficiently among other CDs. Maltose and pullulan were not utilized as substrates. Linear maltodextrins with a small glucose unit were very slowly hydrolyzed, and starch was hydrolyzed more slowly. Analysis by thin-layer chromatography revealed that glucose and maltose were produced as end products. The purified recombinant CBP bound to maltose as well as to alpha-CD. However, the CBP exhibited higher thermostability in the presence of alpha-CD. These results suggested that strain B1001 possesses a unique metabolic pathway that includes extracellular synthesis, transmembrane uptake, and intracellular degradation of CDs in starch utilization. Potential advantages of this starch metabolic pathway via CDs are discussed.
Collapse
|
12
|
Sauer J, Sigurskjold BW, Christensen U, Frandsen TP, Mirgorodskaya E, Harrison M, Roepstorff P, Svensson B. Glucoamylase: structure/function relationships, and protein engineering. BIOCHIMICA ET BIOPHYSICA ACTA 2000; 1543:275-293. [PMID: 11150611 DOI: 10.1016/s0167-4838(00)00232-6] [Citation(s) in RCA: 126] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Glucoamylases are inverting exo-acting starch hydrolases releasing beta-glucose from the non-reducing ends of starch and related substrates. The majority of glucoamylases are multidomain enzymes consisting of a catalytic domain connected to a starch-binding domain by an O-glycosylated linker region. Three-dimensional structures have been determined of free and inhibitor complexed glucoamylases from Aspergillus awamori var. X100, Aspergillus niger, and Saccharomycopsis fibuligera. The catalytic domain folds as a twisted (alpha/alpha)(6)-barrel with a central funnel-shaped active site, while the starch-binding domain folds as an antiparallel beta-barrel and has two binding sites for starch or beta-cyclodextrin. Certain glucoamylases are widely applied industrially in the manufacture of glucose and fructose syrups. For more than a decade mutational investigations of glucoamylase have addressed fundamental structure/function relationships in the binding and catalytic mechanisms. In parallel, issues of relevance for application have been pursued using protein engineering to improve the industrial properties. The present review focuses on recent findings on the catalytic site, mechanism of action, substrate recognition, the linker region, the multidomain architecture, the engineering of specificity and stability, and roles of individual substrate binding subsites.
Collapse
Affiliation(s)
- J Sauer
- Department of Chemistry, Carlsberg Laboratory, Gamle Carlsberg Vej 10, DK-2500 Copenhagen, Valby, Denmark
| | | | | | | | | | | | | | | |
Collapse
|
13
|
Ohdan K, Kuriki T, Takata H, Kaneko H, Okada S. Introduction of raw starch-binding domains into Bacillus subtilis alpha-amylase by fusion with the starch-binding domain of Bacillus cyclomaltodextrin glucanotransferase. Appl Environ Microbiol 2000; 66:3058-64. [PMID: 10877806 PMCID: PMC92111 DOI: 10.1128/aem.66.7.3058-3064.2000] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We constructed two types of chimeric enzymes, Ch1 Amy and Ch2 Amy. Ch1 Amy consisted of a catalytic domain of Bacillus subtilis X-23 alpha-amylase (Ba-S) and the raw starch-binding domain (domain E) of Bacillus A2-5a cyclomaltodextrin glucanotransferase (A2-5a CGT). Ch2 Amy consisted of Ba-S and D (function unknown) plus E domains of A2-5a CGT. Ch1 Amy acquired raw starch-binding and -digesting abilities which were not present in the catalytic part (Ba-S). Furthermore, the specific activity of Ch1 Amy was almost identical when enzyme activity was evaluated on a molar basis. Although Ch2 Amy exhibited even higher raw starch-binding and -digesting abilities than Ch1 Amy, the specific activity was lower than that of Ba-S. We did not detect any differences in other enzymatic characteristics (amylolytic pattern, transglycosylation ability, effects of pH, and temperature on stability and activity) among Ba-S, Ch1 Amy, and Ch2 Amy.
Collapse
Affiliation(s)
- K Ohdan
- Biochemical Research Laboratory, Ezaki Glico Co., Ltd., Utajima 4-6-5, Nishiyodogawa-ku, Osaka 555-8502, Japan
| | | | | | | | | |
Collapse
|
14
|
Zhao J, Chen YH, Kwan HS. Molecular cloning, characterization, and differential expression of a glucoamylase gene from the basidiomycetous fungus Lentinula edodes. Appl Environ Microbiol 2000; 66:2531-5. [PMID: 10831434 PMCID: PMC110576 DOI: 10.1128/aem.66.6.2531-2535.2000] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The complete nucleotide sequence of putative glucoamylase gene gla1 from the basidiomycetous fungus Lentinula edodes strain L54 is reported. The coding region of the genomic glucoamylase sequence, which is preceded by eukaryotic promoter elements CAAT and TATA, spans 2,076 bp. The gla1 gene sequence codes for a putative polypeptide of 571 amino acids and is interrupted by seven introns. The open reading frame sequence of the gla1 gene shows strong homology with those of other fungal glucoamylase genes and encodes a protein with an N-terminal catalytic domain and a C-terminal starch-binding domain. The similarity between the Gla1 protein and other fungal glucoamylases is from 45 to 61%, with the region of highest conservation found in catalytic domains and starch-binding domains. We compared the kinetics of glucoamylase activity and levels of gene expression in L. edodes strain L54 grown on different carbon sources (glucose, starch, cellulose, and potato extract) and in various developmental stages (mycelium growth, primordium appearance, and fruiting body formation). Quantitative reverse transcription PCR utilizing pairs of primers specific for gla1 gene expression shows that expression of gla1 was induced by starch and increased during the process of fruiting body formation, which indicates that glucoamylases may play an important role in the morphogenesis of the basidiomycetous fungus.
Collapse
MESH Headings
- Amino Acid Sequence
- Cloning, Molecular
- Culture Media
- Gene Expression Regulation, Fungal
- Genes, Fungal
- Genomic Library
- Glucan 1,4-alpha-Glucosidase/chemistry
- Glucan 1,4-alpha-Glucosidase/genetics
- Glucan 1,4-alpha-Glucosidase/metabolism
- Lentinula/enzymology
- Lentinula/genetics
- Lentinula/growth & development
- Molecular Sequence Data
- Promoter Regions, Genetic
- Reverse Transcriptase Polymerase Chain Reaction/methods
- Sequence Analysis, DNA
- Terminator Regions, Genetic
- Transcription, Genetic
Collapse
Affiliation(s)
- J Zhao
- Department of Biology, The Chinese University of Hong Kong, Shatin, N. T., Hong Kong SAR, People's Republic of China
| | | | | |
Collapse
|
15
|
Ohdan K, Kuriki T, Kaneko H, Shimada J, Takada T, Fujimoto Z, Mizuno H, Okada S. Characteristics of two forms of alpha-amylases and structural implication. Appl Environ Microbiol 1999; 65:4652-8. [PMID: 10508102 PMCID: PMC91620 DOI: 10.1128/aem.65.10.4652-4658.1999] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Complete (Ba-L) and truncated (Ba-S) forms of alpha-amylases from Bacillus subtilis X-23 were purified, and the amino- and carboxyl-terminal amino acid sequences of Ba-L and Ba-S were determined. The amino acid sequence deduced from the nucleotide sequence of the alpha-amylase gene indicated that Ba-S was produced from Ba-L by truncation of the 186 amino acid residues at the carboxyl-terminal region. The results of genomic Southern analysis and Western analysis suggested that the two enzymes originated from the same alpha-amylase gene and that truncation of Ba-L to Ba-S occurred during the cultivation of B. subtilis X-23 cells. Although the primary structure of Ba-S was approximately 28% shorter than that of Ba-L, the two enzyme forms had the same enzymatic characteristics (molar catalytic activity, amylolytic pattern, transglycosylation ability, effect of pH on stability and activity, optimum temperature, and raw starch-binding ability), except that the thermal stability of Ba-S was higher than that of Ba-L. An analysis of the secondary structure as well as the predicted three-dimensional structure of Ba-S showed that Ba-S retained all of the necessary domains (domains A, B, and C) which were most likely to be required for functionality as alpha-amylase.
Collapse
Affiliation(s)
- K Ohdan
- Biochemical Research Laboratory, Ezaki Glico Co., Ltd., Utajima 4-6-5, Nishiyodogawa-ku, Osaka 555-8502, Japan
| | | | | | | | | | | | | | | |
Collapse
|
16
|
Erra-Pujada M, Debeire P, Duchiron F, O'Donohue MJ. The type II pullulanase of Thermococcus hydrothermalis: molecular characterization of the gene and expression of the catalytic domain. J Bacteriol 1999; 181:3284-7. [PMID: 10322035 PMCID: PMC93789 DOI: 10.1128/jb.181.10.3284-3287.1999] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The gene encoding a hyperthermostable type II pullulanase produced by Thermococcus hydrothermalis (Th-Apu) has been isolated. Analysis of a total of 5.2 kb of genomic DNA has revealed the presence of three open reading frames, one of which (apuA) encodes the pullulanase. This enzyme is composed of 1,339 amino acid residues and exhibits a multidomain structure. In addition to a typical N-terminal signal peptide, Th-Apu possesses a catalytic domain, a domain bearing S-layer homology-like motifs, a Thr-rich region, and a potential C-terminal transmembrane domain. The presence of these noncatalytic domains suggests that Th-Apu may be anchored to the cell surface and be O glycosylated.
Collapse
Affiliation(s)
- M Erra-Pujada
- Unit¿e de Physicochimie et Biotechnologie des Polymères, Institut National de la Recherche Agronomique, 51687 Reims Cedex 02, France
| | | | | | | |
Collapse
|
17
|
Goto M, Tsukamoto M, Kwon I, Ekino K, Furukawa K. Functional analysis of O-linked oligosaccharides in threonine/serine-rich region of Aspergillus glucoamylase by expression in mannosyltransferase-disruptants of yeast. EUROPEAN JOURNAL OF BIOCHEMISTRY 1999; 260:596-602. [PMID: 10102986 DOI: 10.1046/j.1432-1327.1999.00207.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The glaA gene encoding glucoamylase I (GAI) of Aspergillus awamori var. kawachi was heterologously expressed in mannosyltransferase mutants of Saccharomyces cerevisiae, in which the pmt1 gene and the kre2 gene were disrupted. The GAI enzymes expressed in these yeast mutant cells exhibited a lesser extent of O-glycosylation. Secretion of GAI expressed in the pmt1-disruptant and in the kre2-disruptant, respectively, was almost the same as that of GAI expressed in wild type (wt) strains. The number of O-linked mannose in GAI from wt yeast strain ranged in size from one (Man1) to five (Man5). On the other hand, the O-linked oligosaccharides of GAI from the pmt1-disruptant ranged in size from Man1 to Man4. Man5 was not detected and Man2-Man4 were reduced in proportion to the reduction of Man1. The O-linked oligosaccharides of GAI from the kre2-disruptant ranged from Man1 to Man4, and the molar amount of Man4 was reduced to 27.3%, compared to that of the wt strain. The hydrolyzing abilities for soluble starch and the adsorbing abilities on raw starch were comparable between both disruptants and wt strains. However, the digesting abilities for raw starch of the disruptants were decreased to 70% of those of the wt strains. Stabilities of GAI of the disruptants were reduced toward extreme pH and high temperature, compared to those of the wt strains. These results demonstrate that the O-linked oligosaccharides of GAI are responsible for the enzyme stability and activity toward insoluble substrates but not for secretion.
Collapse
Affiliation(s)
- M Goto
- Laboratory of Applied Microbiology, Departemnt of Agricultural Chemistry, Kyushu University, Hakozaki, Fukuoka, Japan.
| | | | | | | | | |
Collapse
|
18
|
Nojiri M, Saito T. Structure and function of poly(3-hydroxybutyrate) depolymerase from Alcaligenes faecalis T1. J Bacteriol 1997; 179:6965-70. [PMID: 9371441 PMCID: PMC179635 DOI: 10.1128/jb.179.22.6965-6970.1997] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Poly(3-hydroxybutyrate) (PHB) depolymerase from Alcaligenes faecalis T1 is composed of three domains: the catalytic (C) domain, the fibronectin type III-like (F) domain, and the substrate-binding (S) domain. We constructed domain deletion, inversion, chimera, and extra-F-domain mutants and examined their enzyme activity and PHB-binding ability. In addition, we performed substitution of 214Asp and 273His with glycine and aspartate, respectively, to examine their participation in a catalytic triad together with 139Ser. The mutant with both the F and S domains deleted and the trypsin-digested enzyme showed no PHB-hydrolyzing activity and less PHB-binding ability than that of the wild-type enzyme but retained D-(-)-3-hydroxybutyrate trimer-hydrolyzing activity at a level similar to that of the wild-type enzyme. The mutant with the F domain deleted and the mutant which had the order of the F and S domains inverted retained PHB-binding ability and trimer-hydrolyzing activity at levels similar to those of the wild-type enzyme but lost PHB-hydrolyzing activity. The chimera mutant, in which the F domain was substituted with a Thr-rich domain of PHB depolymerase A from Pseudomonas lemoignei, and the extra-F-domain mutant, with an additional F domain, retained trimer- and PHB-hydrolyzing activities and PHB-binding ability at levels similar to those of the wild-type enzyme. Two mutants (D214G and H273D) showed no enzymatic activity toward trimer and PHB, and they were not labeled with [3H]diisopropylfluorophosphate.
Collapse
Affiliation(s)
- M Nojiri
- Department of Biological Sciences, Faculty of Science, Kanagawa University, Hiratsuka, Japan
| | | |
Collapse
|
19
|
Goto M, Ekino K, Furukawa K. Expression and functional analysis of a hyperglycosylated glucoamylase in a parental host, Aspergillus awamori var. kawachi. Appl Environ Microbiol 1997; 63:2940-3. [PMID: 9212440 PMCID: PMC168589 DOI: 10.1128/aem.63.7.2940-2943.1997] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
A modified glucoamylase gene (glaA) with an extra Thr- and Ser-rich Gp-I domain (T. Semimaru, M. Goto, K. Furukawa, and S. Hayashida, Appl. Environ. Microbiol. 61:2885-2890, 1995) was introduced into a mutant parental host, Aspergillus awamori var. kawachi, in which the original glaA gene had been completely deleted and replaced with the hygromycin phosphotransferase gene. The modified glaA was successfully expressed and secreted. The modified glucoamylase possessed higher digestibility of raw corn starch and higher stabilities in response to heat and extreme pH.
Collapse
Affiliation(s)
- M Goto
- Department of Agricultural Chemistry, Kyushu University, Fukuoka, Japan.
| | | | | |
Collapse
|
20
|
Iefuji H, Chino M, Kato M, Iimura Y. Raw-starch-digesting and thermostable alpha-amylase from the yeast Cryptococcus sp. S-2: purification, characterization, cloning and sequencing. Biochem J 1996; 318 ( Pt 3):989-96. [PMID: 8836148 PMCID: PMC1217715 DOI: 10.1042/bj3180989] [Citation(s) in RCA: 94] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
A starch-degrading enzyme produced by the yeast Cryptococcus sp. S-2 was purified in only one step by using an alpha-cyclodextrin-Sepharose 6B column, and was characterized as an alpha-amylase (EC 3.2.1.1). The molecular mass and isoelectric point of purified alpha-amylase (AMY-CS2) were estimated to be 66 kDa and 4.2 respectively. AMY-CS2 has raw-starch-digesting and raw-starch-absorbing activities. Furthermore it was shown to be thermostable. An open reading frame of the cDNA specified 611 amino acids, including a putative signal peptide of 20 amino acids. The N-terminal region of AMY-CS2 (from the N-terminus to position 496) had 49.7% similarity with the whole region of alpha-amylase from Aspergillus oryzae (Taka-amylase), whereas the C-terminal region had a sequence that was similar to the C-terminal region of glucoamylase G1 from A. niger. In addition, putative raw-starch-binding motifs exist in some amylolytic enzymes. A mutant AMY-CS2 that lacks the C-terminal domain lost not only its ability to bind or digest raw starch, but also its thermostability. Consequently it is possible that the putative raw-starch-binding domain of AMY-CS2 plays a role not only in the molecule's raw-starch-digesting ability but also in its thermostability.
Collapse
Affiliation(s)
- H Iefuji
- National Research Institute of Brewing, Higashi-Hiroshima, Japan
| | | | | | | |
Collapse
|