Abstract:
:Enhancement of enzyme thermostability by protein engineering gives us information about the thermostabilization mechanism as well as advantages for industrial use of enzymes. In this study, we enhanced the thermostability of endoglucanase EngB, one component of the cellulase complex (cellulosome) from Clostridium cellulovorans, by the directed evolution technique. The library was constructed by in vitro recombination of the genes for EngB and non-cellulosomal cellulase EngD, based on the fact that the catalytic domains of both cellulases were highly homologous. To obtain thermostable clones without loss of activity, the library was screened by a combination of activity and thermostability screening. We obtained three mutants out of 8000 selected clones that showed significantly higher thermostability than those of EngB and EngD without compromising their endoglucanase activities. One of the mutants possessed a sevenfold higher thermostability than EngB. The possible mechanisms of thermostabilization are discussed.
journal_name
Mol Microbioljournal_title
Molecular microbiologyauthors
Murashima K,Kosugi A,Doi RHdoi
10.1046/j.1365-2958.2002.03049.xsubject
Has Abstractpub_date
2002-08-01 00:00:00pages
617-26issue
3eissn
0950-382Xissn
1365-2958pii
3049journal_volume
45pub_type
杂志文章abstract::Cpmk2, encoding a mitogen-activated protein (MAP) kinase from the ascomycete Claviceps purpurea, is an orthologue of SLT2 from Saccharomyces cerevisiae, the first isolated from a biotrophic, non-appressorium-forming pathogen. Deletion mutants obtained by a gene replacement approach show impaired vegetative properties ...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1046/j.1365-2958.2002.03133.x
更新日期:2002-10-01 00:00:00
abstract::Saccharomyces cerevisiae neutral trehalase, encoded by NTH1, controls trehalose hydrolysis in response to multiple stress conditions, including nutrient limitation. The presence of three stress responsive elements (STREs, CCCCT) in the NTH1 promoter suggested that the transcriptional activator proteins Msn2 and Msn4, ...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1046/j.1365-2958.2000.01706.x
更新日期:2000-01-01 00:00:00
abstract::The Leishmania major aquaglyceroporin, LmAQP1, is responsible for the transport of trivalent metalloids, arsenite and antimonite. We have earlier shown that downregulation of LmAQP1 provides resistance to trivalent antimony compounds whereas increased expression of LmAQP1 in drug-resistant parasites can reverse the re...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/j.1365-2958.2007.05845.x
更新日期:2007-08-01 00:00:00
abstract::Clusters of regularly interspaced short palindromic repeats (CRISPRs) of Sulfolobus fall into three main families based on their repeats, leader regions, associated cas genes and putative recognition sequences on viruses and plasmids. Spacer sequence matches to different viruses and plasmids of the Sulfolobales reveal...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/j.1365-2958.2009.06641.x
更新日期:2009-04-01 00:00:00
abstract::Prediction studies, conformational analyses and membrane-topology mapping lead to the conclusion that the penicillin sensory transducer, BlaR, involved in the inducibility of beta-lactamase synthesis in Bacillus licheniformis, is embedded in the plasma membrane bilayer via four transmembrane segments TM1-TM4 that form...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1046/j.1365-2958.1997.2761642.x
更新日期:1997-03-01 00:00:00
abstract::The archaeal transcription apparatus is chimeric: its core components (RNA polymerase and basal factors) closely resemble those of eukaryotic RNA polymerase II, but the putative archaeal transcriptional regulators are overwhelmingly of bacterial type. Particular interest attaches to how these bacterial-type effectors,...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/j.1365-2958.2005.04563.x
更新日期:2005-05-01 00:00:00
abstract::We show that Yersinia pestis and pesticin-sensitive isolates of Y. pseudotuberculosis possess a common 34 kbp DNA region that has all the hallmarks of a pathogenicity island and is inserted into different asparaginyl tRNA genes at different chromosomal locations in each species. This pathogenicity island (YP-HPI) is m...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1046/j.1365-2958.1999.01172.x
更新日期:1999-01-01 00:00:00
abstract::Chlamydiae are obligate intracellular bacteria which undergo a unique developmental cycle, alternating between non-replicative elementary bodies (EBs) and replicative reticulate bodies (RBs). The transition from RB to EB is characterized by condensation of the chromosome into a dense nucleoid structure. The chlamydial...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/j.1365-2958.1993.tb01689.x
更新日期:1993-07-01 00:00:00
abstract::We have identified gene fusions of polyamine biosynthetic enzymes S-adenosylmethionine decarboxylase (AdoMetDC, speD) and aminopropyltransferase (speE) orthologues in diverse bacterial phyla. Both domains are functionally active and we demonstrate the novel de novo synthesis of the triamine spermidine from the diamine...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/j.1365-2958.2011.07757.x
更新日期:2011-08-01 00:00:00
abstract::The monocistronic transcript of rpsO undergoes an endonucleolytic cleavage downstream of the coding sequence, which removes the hairpin of the transcription terminator and initiates the rapid degradation of the message. We demonstrate here that the two rne-dependent cleavages, on both sides of the transcription termin...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1046/j.1365-2958.1996.440971.x
更新日期:1996-03-01 00:00:00
abstract::The role of cAMP signalling during germination of asexual spores (conidia) of the filamentous fungus Aspergillus nidulans was investigated. A. nidulans strains defective for adenylate cyclase (CyaA) or for the functionally overlapping cAMP-dependent protein kinase (PkaA) and newly characterized SchA protein kinase, ho...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1046/j.1365-2958.2002.02933.x
更新日期:2002-05-01 00:00:00
abstract::Platelet binding by Streptococcus gordonii strain M99 is strongly correlated with the expression of the large surface glycoprotein GspB. A 14 kb chromosomal region downstream of gspB was previously shown to be required for the expression of this protein. The region encodes SecA2 and SecY2, which are components of an a...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/j.1365-2958.2004.03978.x
更新日期:2004-04-01 00:00:00
abstract::The kinetics of initiation of chromosome replication after induction of DnaA protein synthesis was studied in a dnaA(nuII) rnh mutant of Escherichia coli. DnaA protein synthesis was induced to different extents using the wild-type dnaA gene controlled by a lac promoter. Initiation of chromosome replication from oriC, ...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/j.1365-2958.1995.tb02229.x
更新日期:1995-01-01 00:00:00
abstract::Amino acid sequence analyses have indicated that the amino-terminal part of bacteriophage PRD1 structural protein P7 carries a conserved transglycosylase domain. We analysed wild-type PRD1 and different mutant particles in zymograms and found a glycolytic activity that was associated with protein P7. This is the first...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1046/j.1365-2958.2000.01996.x
更新日期:2000-07-01 00:00:00
abstract::Cell differentiation is widespread during the development of multicellular organisms, but rarely observed in prokaryotes. One example of prokaryotic differentiation is the gram-negative bacterium Myxococcus xanthus. In response to starvation, this gliding bacterium initiates a complex developmental programme that resu...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/j.1365-2958.2009.06879.x
更新日期:2009-10-01 00:00:00
abstract::Superoxide dismutase, catalase, glutathione peroxidase and peroxiredoxins form an antioxidant network protecting cells against reactive oxygen species (ROS). Catalase is a potent H2O2-detoxifying enzyme, which is unexpectedly absent in some members of the Kinetoplastida and Apicomplexa, but present in Toxoplasma gondi...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1046/j.1365-2958.2003.03823.x
更新日期:2004-01-01 00:00:00
abstract::The S box transcription termination control system regulates expression of genes involved in methionine metabolism. Expression of the S box regulon, comprised of 11 transcriptional units in Bacillus subtilis, is induced in response to starvation for methionine. We previously demonstrated that S-adenosylmethionine (SAM...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/j.1365-2958.2005.04740.x
更新日期:2005-08-01 00:00:00
abstract::We previously identified three well-dispersed mutations, E978-K, F989-L and D1009-R within the haemolysin A signal region, located at positions -46, -35 and -15, with respect to the C-terminus, respectively. Each mutation reduces the efficiency of secretion two- to threefold leaving 30-45% of the wild-type activity. W...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/j.1365-2958.1994.tb00293.x
更新日期:1994-01-01 00:00:00
abstract::Streptomyces lividans has a novel DNA modification, which sensitises its DNA to degradation during electrophoresis (the Dnd phenotype). The entire gene cluster (dnd) involved in this modification was localized on an 8 kb DNA fragment and was expressed in a S. lividans deletion mutant (dnd) and in several heterologous ...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/j.1365-2958.2005.04764.x
更新日期:2005-09-01 00:00:00
abstract::The chaperone/usher (CU) pathway is a conserved bacterial secretion system that assembles adhesive fibres termed pili or fimbriae. Pilus biogenesis by the CU pathway requires a periplasmic chaperone and an outer membrane (OM) assembly platform termed the usher. The usher catalyses formation of subunit-subunit interact...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/j.1365-2958.2010.07505.x
更新日期:2011-02-01 00:00:00
abstract::Dynamic oscillation of the Min system in Escherichia coli determines the placement of the division plane at the midcell. In addition to stimulating MinD ATPase activity, we report here that MinE can directly interact with the membrane and this interaction contributes to the proper MinDE localization and dynamics. The ...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/j.1365-2958.2009.07006.x
更新日期:2010-01-01 00:00:00
abstract::The fimbrial and afimbrial adhesins of the Dr family mediate the adherence of uropathogenic and diarrhoea-associated Escherichia coli to decay-accelerating factor (DAF) present on erythrocytes and other cell types. The Dr haemagglutinin binds type IV collagen and, unlike other members of the Dr family, mediates an adh...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1046/j.1365-2958.1997.2231590.x
更新日期:1997-01-01 00:00:00
abstract::Because the ferric uptake regulator (fur) appears to be an essential gene in Pseudomonas aeruginosa, resistance to manganese was used as an enrichment to isolate strains carrying point mutations in the fur gene in order to assess its role in the co-ordinate expression of siderophores and exotoxin A (ETA). This report ...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1046/j.1365-2958.1996.381426.x
更新日期:1996-09-01 00:00:00
abstract::The 29 kDa protein of pathogenic Entamoeba histolytica is a cysteine-rich surface antigen which we recently characterized by cDNA sequencing and by using monoclonal antibodies which differentiated between pathogenic and non-pathogenic clinical isolates. To determine the structure and biochemical attributes of this pro...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/j.1365-2958.1993.tb01166.x
更新日期:1993-03-01 00:00:00
abstract::We report here the formation of symbiotic plasmids (pSyms), by genetic recombination between rearranged pSyms, which lack symbiotic information, and resistance plasmids carrying parts of different symbiotic plasmids (R's). This recombination was found to occur both between plasmids derived from different Rhizobium pha...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/j.1365-2958.1991.tb00765.x
更新日期:1991-04-01 00:00:00
abstract::One often compares cells to computers, and signalling proteins to transistors. Location and wiring of those molecular transistors is paramount in defining the function of the subcellular chips. The bacterial chemotactic sensing apparatus is a large, stable assembly consisting of thousands of receptors, signal transduc...
journal_title:Molecular microbiology
pub_type: 评论,杂志文章
doi:10.1111/j.1365-2958.2008.06240.x
更新日期:2008-07-01 00:00:00
abstract::It has been hypothesized that the dinR gene product of Bacillus subtilis acts as a repressor of the SOS regulon by binding to DNA sequences located upstream of SOS genes, including dinR and recA. Following activation as a result of DNA damage, RecA is believed to catalyse DinR-autocleavage, thus derepressing the SOS r...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/j.1365-2958.1996.tb02657.x
更新日期:1996-10-01 00:00:00
abstract::RbpA is an RNA polymerase-binding protein that occurs in the actinomycete family of bacteria and is regulated by the disulphide stress-response sigma factor, sigma(R), in Streptomyces coelicolor. Here we demonstrate that rbpA null mutants exhibit a slow-growth phenotype and are particularly sensitive to the transcript...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/j.1365-2958.2006.05116.x
更新日期:2006-05-01 00:00:00
abstract::Genetic exchange by natural transformation in Streptococcus pneumoniae occurs in a cell-density dependent process and is initiated by a small extracellular signalling molecule, the competence-stimulating peptide (CSP). comC, the gene for this peptide, has previously been identified and encodes a 44 amino acid pre-pept...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1046/j.1365-2958.1997.2481617.x
更新日期:1997-02-01 00:00:00
abstract::We have determined the sizes of the chromosomes of six Bacillus cereus strains (range 2.4-4.3 Mb) and constructed a physical map of the smallest B. cereus chromosome (2.4 Mb). This map was compared to those of the chromosomes of four B. cereus strains and one B. thuringiensis strain previously determined to be 5.4-6.3...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/j.1365-2958.1994.tb00411.x
更新日期:1994-07-01 00:00:00