S-layer gene sbsC of Bacillus stearothermophilus ATCC 12980: molecular characterization and heterologous expression in Escherichia coli

Zentrum für Ultrastrukturforschung und Ludwig Boltzmann-Institut für Molekulare Nanotechnologie, Universität für Bodenkultur, 1180 Vienna, Austria 1 Institut für Angewandte Mikrobiologie, Universität für Bodenkultur, 1190 Vienna, Austria 2 Author for correspondence: Margit Sára. Tel: +43 1 47 654 22...

Ausführliche Beschreibung

Gespeichert in:
Bibliographische Detailangaben
Veröffentlicht in:Microbiology (Society for General Microbiology) 2000-02, Vol.146 (2), p.273-281
Hauptverfasser: Jarosch, Marina, Egelseer, Eva M, Mattanovich, Diethard, Sleytr, Uwe B, Sara, Margit
Format: Artikel
Sprache:eng
Schlagworte:
Online-Zugang:Volltext
Tags: Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
container_end_page 281
container_issue 2
container_start_page 273
container_title Microbiology (Society for General Microbiology)
container_volume 146
creator Jarosch, Marina
Egelseer, Eva M
Mattanovich, Diethard
Sleytr, Uwe B
Sara, Margit
description Zentrum für Ultrastrukturforschung und Ludwig Boltzmann-Institut für Molekulare Nanotechnologie, Universität für Bodenkultur, 1180 Vienna, Austria 1 Institut für Angewandte Mikrobiologie, Universität für Bodenkultur, 1190 Vienna, Austria 2 Author for correspondence: Margit Sára. Tel: +43 1 47 654 2208. Fax: +43 1 47 89112. e-mail: sara{at}edv1.boku.ac.at The cell surface of Bacillus stearothermophilus ATCC 12980 is completely covered with an oblique S-layer lattice. To investigate sequence identities and a common structure–function relationship in S-layer proteins of different B. stearothermophilus wild-type strains, the nucleotide sequence encoding theS-layer protein SbsC of B . stearothermophilus ATCC 12980 was determined by PCR techniques. The entire sbsC sequence showed an ORF of 3297 bp predicted to encode a protein of 1099 aa with a theoretical molecular mass of 115409 Da and an isoelectric point of 5·73. Primer extension analysis suggested the existence of two promoter regions. Amino acid sequence comparison between SbsC and SbsA, a previously characterized S-layer protein of B. stearothermophilus PV72/p6 which assembles into a hexagonally ordered lattice, revealed an identical secretion signal peptide, 85% identity for theN-terminal regions (aa 31–270) which do not carry any S-layer homologous motifs, but only 21% identity for the rest of the sequences. Affinity studies demonstrated that the N-terminal part of SbsC is necessary for recognition of a secondary cell wall polymer. This was in accordance with results obtained in a previous study for SbsA, thus confirming a common functional principle for the N-terminal parts of both S-layer proteins. The sbsC coding region cloned into the pET3a vector without its own upstream region, the signal sequence and the 3' transcriptional terminator led to stable expression in Escherichia coli . Keywords: S-layer protein, Bacillus stearothermophilus , promoter, heterologous expression, secondary cell wall polymer Abbreviations: SCWP, secondary cell wall polymer; SLH, S-layer homologous The GenBank accession number for the sequence described in this paper is AF055578 .
doi_str_mv 10.1099/00221287-146-2-273
format Article
fullrecord <record><control><sourceid>proquest_pubme</sourceid><recordid>TN_cdi_proquest_miscellaneous_70945112</recordid><sourceformat>XML</sourceformat><sourcesystem>PC</sourcesystem><sourcerecordid>17495500</sourcerecordid><originalsourceid>FETCH-LOGICAL-h232t-faf929505fefdbc380126d31e3d2e7c7db012866ea448dfd60aee907770479423</originalsourceid><addsrcrecordid>eNqFkctu1TAQhiMEohd4ARbIC4TYGMZ2Etvs2qgFpEosKOto4kxOjJz4YOcIygvw2rjqQSxZzeifby6av6peCHgrwNp3AFIKaTQXdcsll1o9qk5L3nAJBh6XXDXAwWh5Up3l_A2gFEE8rU4EaDCqbU6r3194wDtKbEcrsTzkjsWJXaLzIRwyyxthittMaYn72d9LF7ddx4S0Bt6zJQZyh4CJuRkTuo2S_4WbjyvDdWQzFSGGuIulj37uE-V8X_Mru8quDPVu9shcDP5Z9WTCkOn5MZ5XX6-vbruP_Obzh0_dxQ2fpZIbn3Cy0jbQTDSNg1MGhGxHJUiNkrTT41AE07aEdW3GaWwBiSxoraHWtpbqvHr9MHef4vcD5a1ffHYUAq5Uruw12LoR4v-g0LVtGoACvjyCh2Ghsd8nv2C66__-uACvjgBmh2FKuDqf_3FKGmV1wd48YLPfzT98or5YsniX4uBjWe6Keb3si8vqD0Vamh0</addsrcrecordid><sourcetype>Aggregation Database</sourcetype><iscdi>true</iscdi><recordtype>article</recordtype><pqid>17495500</pqid></control><display><type>article</type><title>S-layer gene sbsC of Bacillus stearothermophilus ATCC 12980: molecular characterization and heterologous expression in Escherichia coli</title><source>MEDLINE</source><source>PubMed Central</source><creator>Jarosch, Marina ; Egelseer, Eva M ; Mattanovich, Diethard ; Sleytr, Uwe B ; Sara, Margit</creator><creatorcontrib>Jarosch, Marina ; Egelseer, Eva M ; Mattanovich, Diethard ; Sleytr, Uwe B ; Sara, Margit</creatorcontrib><description>Zentrum für Ultrastrukturforschung und Ludwig Boltzmann-Institut für Molekulare Nanotechnologie, Universität für Bodenkultur, 1180 Vienna, Austria 1 Institut für Angewandte Mikrobiologie, Universität für Bodenkultur, 1190 Vienna, Austria 2 Author for correspondence: Margit Sára. Tel: +43 1 47 654 2208. Fax: +43 1 47 89112. e-mail: sara{at}edv1.boku.ac.at The cell surface of Bacillus stearothermophilus ATCC 12980 is completely covered with an oblique S-layer lattice. To investigate sequence identities and a common structure–function relationship in S-layer proteins of different B. stearothermophilus wild-type strains, the nucleotide sequence encoding theS-layer protein SbsC of B . stearothermophilus ATCC 12980 was determined by PCR techniques. The entire sbsC sequence showed an ORF of 3297 bp predicted to encode a protein of 1099 aa with a theoretical molecular mass of 115409 Da and an isoelectric point of 5·73. Primer extension analysis suggested the existence of two promoter regions. Amino acid sequence comparison between SbsC and SbsA, a previously characterized S-layer protein of B. stearothermophilus PV72/p6 which assembles into a hexagonally ordered lattice, revealed an identical secretion signal peptide, 85% identity for theN-terminal regions (aa 31–270) which do not carry any S-layer homologous motifs, but only 21% identity for the rest of the sequences. Affinity studies demonstrated that the N-terminal part of SbsC is necessary for recognition of a secondary cell wall polymer. This was in accordance with results obtained in a previous study for SbsA, thus confirming a common functional principle for the N-terminal parts of both S-layer proteins. The sbsC coding region cloned into the pET3a vector without its own upstream region, the signal sequence and the 3' transcriptional terminator led to stable expression in Escherichia coli . Keywords: S-layer protein, Bacillus stearothermophilus , promoter, heterologous expression, secondary cell wall polymer Abbreviations: SCWP, secondary cell wall polymer; SLH, S-layer homologous The GenBank accession number for the sequence described in this paper is AF055578 .</description><identifier>ISSN: 1350-0872</identifier><identifier>EISSN: 1465-2080</identifier><identifier>DOI: 10.1099/00221287-146-2-273</identifier><identifier>PMID: 10708365</identifier><language>eng</language><publisher>Reading: Soc General Microbiol</publisher><subject>Bacillus stearothermophilus ; Bacterial Proteins - chemistry ; Bacterial Proteins - genetics ; Bacterial Proteins - metabolism ; Bacteriology ; Base Sequence ; Biological and medical sciences ; Blotting, Northern ; Cell Wall - metabolism ; Cloning, Molecular ; DNA Primers ; DNA, Bacterial - analysis ; DNA, Bacterial - genetics ; Electrophoresis, Polyacrylamide Gel ; Escherichia coli ; Escherichia coli - genetics ; Escherichia coli - metabolism ; Fundamental and applied biological sciences. Psychology ; Genetics ; Geobacillus stearothermophilus - genetics ; Geobacillus stearothermophilus - growth &amp; development ; Geobacillus stearothermophilus - metabolism ; Immunoblotting ; Membrane Glycoproteins - chemistry ; Membrane Glycoproteins - genetics ; Membrane Glycoproteins - metabolism ; Microbiology ; Molecular Sequence Data ; Recombinant Proteins - chemistry ; Recombinant Proteins - metabolism ; sbsC gene ; Sequence Analysis, DNA ; Structure-Activity Relationship</subject><ispartof>Microbiology (Society for General Microbiology), 2000-02, Vol.146 (2), p.273-281</ispartof><rights>2000 INIST-CNRS</rights><lds50>peer_reviewed</lds50><woscitedreferencessubscribed>false</woscitedreferencessubscribed></display><links><openurl>$$Topenurl_article</openurl><openurlfulltext>$$Topenurlfull_article</openurlfulltext><thumbnail>$$Tsyndetics_thumb_exl</thumbnail><link.rule.ids>314,777,781,27905,27906</link.rule.ids><backlink>$$Uhttp://pascal-francis.inist.fr/vibad/index.php?action=getRecordDetail&amp;idt=1328397$$DView record in Pascal Francis$$Hfree_for_read</backlink><backlink>$$Uhttps://www.ncbi.nlm.nih.gov/pubmed/10708365$$D View this record in MEDLINE/PubMed$$Hfree_for_read</backlink></links><search><creatorcontrib>Jarosch, Marina</creatorcontrib><creatorcontrib>Egelseer, Eva M</creatorcontrib><creatorcontrib>Mattanovich, Diethard</creatorcontrib><creatorcontrib>Sleytr, Uwe B</creatorcontrib><creatorcontrib>Sara, Margit</creatorcontrib><title>S-layer gene sbsC of Bacillus stearothermophilus ATCC 12980: molecular characterization and heterologous expression in Escherichia coli</title><title>Microbiology (Society for General Microbiology)</title><addtitle>Microbiology</addtitle><description>Zentrum für Ultrastrukturforschung und Ludwig Boltzmann-Institut für Molekulare Nanotechnologie, Universität für Bodenkultur, 1180 Vienna, Austria 1 Institut für Angewandte Mikrobiologie, Universität für Bodenkultur, 1190 Vienna, Austria 2 Author for correspondence: Margit Sára. Tel: +43 1 47 654 2208. Fax: +43 1 47 89112. e-mail: sara{at}edv1.boku.ac.at The cell surface of Bacillus stearothermophilus ATCC 12980 is completely covered with an oblique S-layer lattice. To investigate sequence identities and a common structure–function relationship in S-layer proteins of different B. stearothermophilus wild-type strains, the nucleotide sequence encoding theS-layer protein SbsC of B . stearothermophilus ATCC 12980 was determined by PCR techniques. The entire sbsC sequence showed an ORF of 3297 bp predicted to encode a protein of 1099 aa with a theoretical molecular mass of 115409 Da and an isoelectric point of 5·73. Primer extension analysis suggested the existence of two promoter regions. Amino acid sequence comparison between SbsC and SbsA, a previously characterized S-layer protein of B. stearothermophilus PV72/p6 which assembles into a hexagonally ordered lattice, revealed an identical secretion signal peptide, 85% identity for theN-terminal regions (aa 31–270) which do not carry any S-layer homologous motifs, but only 21% identity for the rest of the sequences. Affinity studies demonstrated that the N-terminal part of SbsC is necessary for recognition of a secondary cell wall polymer. This was in accordance with results obtained in a previous study for SbsA, thus confirming a common functional principle for the N-terminal parts of both S-layer proteins. The sbsC coding region cloned into the pET3a vector without its own upstream region, the signal sequence and the 3' transcriptional terminator led to stable expression in Escherichia coli . Keywords: S-layer protein, Bacillus stearothermophilus , promoter, heterologous expression, secondary cell wall polymer Abbreviations: SCWP, secondary cell wall polymer; SLH, S-layer homologous The GenBank accession number for the sequence described in this paper is AF055578 .</description><subject>Bacillus stearothermophilus</subject><subject>Bacterial Proteins - chemistry</subject><subject>Bacterial Proteins - genetics</subject><subject>Bacterial Proteins - metabolism</subject><subject>Bacteriology</subject><subject>Base Sequence</subject><subject>Biological and medical sciences</subject><subject>Blotting, Northern</subject><subject>Cell Wall - metabolism</subject><subject>Cloning, Molecular</subject><subject>DNA Primers</subject><subject>DNA, Bacterial - analysis</subject><subject>DNA, Bacterial - genetics</subject><subject>Electrophoresis, Polyacrylamide Gel</subject><subject>Escherichia coli</subject><subject>Escherichia coli - genetics</subject><subject>Escherichia coli - metabolism</subject><subject>Fundamental and applied biological sciences. Psychology</subject><subject>Genetics</subject><subject>Geobacillus stearothermophilus - genetics</subject><subject>Geobacillus stearothermophilus - growth &amp; development</subject><subject>Geobacillus stearothermophilus - metabolism</subject><subject>Immunoblotting</subject><subject>Membrane Glycoproteins - chemistry</subject><subject>Membrane Glycoproteins - genetics</subject><subject>Membrane Glycoproteins - metabolism</subject><subject>Microbiology</subject><subject>Molecular Sequence Data</subject><subject>Recombinant Proteins - chemistry</subject><subject>Recombinant Proteins - metabolism</subject><subject>sbsC gene</subject><subject>Sequence Analysis, DNA</subject><subject>Structure-Activity Relationship</subject><issn>1350-0872</issn><issn>1465-2080</issn><fulltext>true</fulltext><rsrctype>article</rsrctype><creationdate>2000</creationdate><recordtype>article</recordtype><sourceid>EIF</sourceid><recordid>eNqFkctu1TAQhiMEohd4ARbIC4TYGMZ2Etvs2qgFpEosKOto4kxOjJz4YOcIygvw2rjqQSxZzeifby6av6peCHgrwNp3AFIKaTQXdcsll1o9qk5L3nAJBh6XXDXAwWh5Up3l_A2gFEE8rU4EaDCqbU6r3194wDtKbEcrsTzkjsWJXaLzIRwyyxthittMaYn72d9LF7ddx4S0Bt6zJQZyh4CJuRkTuo2S_4WbjyvDdWQzFSGGuIulj37uE-V8X_Mru8quDPVu9shcDP5Z9WTCkOn5MZ5XX6-vbruP_Obzh0_dxQ2fpZIbn3Cy0jbQTDSNg1MGhGxHJUiNkrTT41AE07aEdW3GaWwBiSxoraHWtpbqvHr9MHef4vcD5a1ffHYUAq5Uruw12LoR4v-g0LVtGoACvjyCh2Ghsd8nv2C66__-uACvjgBmh2FKuDqf_3FKGmV1wd48YLPfzT98or5YsniX4uBjWe6Keb3si8vqD0Vamh0</recordid><startdate>20000201</startdate><enddate>20000201</enddate><creator>Jarosch, Marina</creator><creator>Egelseer, Eva M</creator><creator>Mattanovich, Diethard</creator><creator>Sleytr, Uwe B</creator><creator>Sara, Margit</creator><general>Soc General Microbiol</general><general>Society for General Microbiology</general><scope>IQODW</scope><scope>CGR</scope><scope>CUY</scope><scope>CVF</scope><scope>ECM</scope><scope>EIF</scope><scope>NPM</scope><scope>7QL</scope><scope>C1K</scope><scope>7X8</scope></search><sort><creationdate>20000201</creationdate><title>S-layer gene sbsC of Bacillus stearothermophilus ATCC 12980: molecular characterization and heterologous expression in Escherichia coli</title><author>Jarosch, Marina ; Egelseer, Eva M ; Mattanovich, Diethard ; Sleytr, Uwe B ; Sara, Margit</author></sort><facets><frbrtype>5</frbrtype><frbrgroupid>cdi_FETCH-LOGICAL-h232t-faf929505fefdbc380126d31e3d2e7c7db012866ea448dfd60aee907770479423</frbrgroupid><rsrctype>articles</rsrctype><prefilter>articles</prefilter><language>eng</language><creationdate>2000</creationdate><topic>Bacillus stearothermophilus</topic><topic>Bacterial Proteins - chemistry</topic><topic>Bacterial Proteins - genetics</topic><topic>Bacterial Proteins - metabolism</topic><topic>Bacteriology</topic><topic>Base Sequence</topic><topic>Biological and medical sciences</topic><topic>Blotting, Northern</topic><topic>Cell Wall - metabolism</topic><topic>Cloning, Molecular</topic><topic>DNA Primers</topic><topic>DNA, Bacterial - analysis</topic><topic>DNA, Bacterial - genetics</topic><topic>Electrophoresis, Polyacrylamide Gel</topic><topic>Escherichia coli</topic><topic>Escherichia coli - genetics</topic><topic>Escherichia coli - metabolism</topic><topic>Fundamental and applied biological sciences. Psychology</topic><topic>Genetics</topic><topic>Geobacillus stearothermophilus - genetics</topic><topic>Geobacillus stearothermophilus - growth &amp; development</topic><topic>Geobacillus stearothermophilus - metabolism</topic><topic>Immunoblotting</topic><topic>Membrane Glycoproteins - chemistry</topic><topic>Membrane Glycoproteins - genetics</topic><topic>Membrane Glycoproteins - metabolism</topic><topic>Microbiology</topic><topic>Molecular Sequence Data</topic><topic>Recombinant Proteins - chemistry</topic><topic>Recombinant Proteins - metabolism</topic><topic>sbsC gene</topic><topic>Sequence Analysis, DNA</topic><topic>Structure-Activity Relationship</topic><toplevel>peer_reviewed</toplevel><toplevel>online_resources</toplevel><creatorcontrib>Jarosch, Marina</creatorcontrib><creatorcontrib>Egelseer, Eva M</creatorcontrib><creatorcontrib>Mattanovich, Diethard</creatorcontrib><creatorcontrib>Sleytr, Uwe B</creatorcontrib><creatorcontrib>Sara, Margit</creatorcontrib><collection>Pascal-Francis</collection><collection>Medline</collection><collection>MEDLINE</collection><collection>MEDLINE (Ovid)</collection><collection>MEDLINE</collection><collection>MEDLINE</collection><collection>PubMed</collection><collection>Bacteriology Abstracts (Microbiology B)</collection><collection>Environmental Sciences and Pollution Management</collection><collection>MEDLINE - Academic</collection><jtitle>Microbiology (Society for General Microbiology)</jtitle></facets><delivery><delcategory>Remote Search Resource</delcategory><fulltext>fulltext</fulltext></delivery><addata><au>Jarosch, Marina</au><au>Egelseer, Eva M</au><au>Mattanovich, Diethard</au><au>Sleytr, Uwe B</au><au>Sara, Margit</au><format>journal</format><genre>article</genre><ristype>JOUR</ristype><atitle>S-layer gene sbsC of Bacillus stearothermophilus ATCC 12980: molecular characterization and heterologous expression in Escherichia coli</atitle><jtitle>Microbiology (Society for General Microbiology)</jtitle><addtitle>Microbiology</addtitle><date>2000-02-01</date><risdate>2000</risdate><volume>146</volume><issue>2</issue><spage>273</spage><epage>281</epage><pages>273-281</pages><issn>1350-0872</issn><eissn>1465-2080</eissn><abstract>Zentrum für Ultrastrukturforschung und Ludwig Boltzmann-Institut für Molekulare Nanotechnologie, Universität für Bodenkultur, 1180 Vienna, Austria 1 Institut für Angewandte Mikrobiologie, Universität für Bodenkultur, 1190 Vienna, Austria 2 Author for correspondence: Margit Sára. Tel: +43 1 47 654 2208. Fax: +43 1 47 89112. e-mail: sara{at}edv1.boku.ac.at The cell surface of Bacillus stearothermophilus ATCC 12980 is completely covered with an oblique S-layer lattice. To investigate sequence identities and a common structure–function relationship in S-layer proteins of different B. stearothermophilus wild-type strains, the nucleotide sequence encoding theS-layer protein SbsC of B . stearothermophilus ATCC 12980 was determined by PCR techniques. The entire sbsC sequence showed an ORF of 3297 bp predicted to encode a protein of 1099 aa with a theoretical molecular mass of 115409 Da and an isoelectric point of 5·73. Primer extension analysis suggested the existence of two promoter regions. Amino acid sequence comparison between SbsC and SbsA, a previously characterized S-layer protein of B. stearothermophilus PV72/p6 which assembles into a hexagonally ordered lattice, revealed an identical secretion signal peptide, 85% identity for theN-terminal regions (aa 31–270) which do not carry any S-layer homologous motifs, but only 21% identity for the rest of the sequences. Affinity studies demonstrated that the N-terminal part of SbsC is necessary for recognition of a secondary cell wall polymer. This was in accordance with results obtained in a previous study for SbsA, thus confirming a common functional principle for the N-terminal parts of both S-layer proteins. The sbsC coding region cloned into the pET3a vector without its own upstream region, the signal sequence and the 3' transcriptional terminator led to stable expression in Escherichia coli . Keywords: S-layer protein, Bacillus stearothermophilus , promoter, heterologous expression, secondary cell wall polymer Abbreviations: SCWP, secondary cell wall polymer; SLH, S-layer homologous The GenBank accession number for the sequence described in this paper is AF055578 .</abstract><cop>Reading</cop><pub>Soc General Microbiol</pub><pmid>10708365</pmid><doi>10.1099/00221287-146-2-273</doi><tpages>9</tpages></addata></record>
fulltext fulltext
identifier ISSN: 1350-0872
ispartof Microbiology (Society for General Microbiology), 2000-02, Vol.146 (2), p.273-281
issn 1350-0872
1465-2080
language eng
recordid cdi_proquest_miscellaneous_70945112
source MEDLINE; PubMed Central
subjects Bacillus stearothermophilus
Bacterial Proteins - chemistry
Bacterial Proteins - genetics
Bacterial Proteins - metabolism
Bacteriology
Base Sequence
Biological and medical sciences
Blotting, Northern
Cell Wall - metabolism
Cloning, Molecular
DNA Primers
DNA, Bacterial - analysis
DNA, Bacterial - genetics
Electrophoresis, Polyacrylamide Gel
Escherichia coli
Escherichia coli - genetics
Escherichia coli - metabolism
Fundamental and applied biological sciences. Psychology
Genetics
Geobacillus stearothermophilus - genetics
Geobacillus stearothermophilus - growth & development
Geobacillus stearothermophilus - metabolism
Immunoblotting
Membrane Glycoproteins - chemistry
Membrane Glycoproteins - genetics
Membrane Glycoproteins - metabolism
Microbiology
Molecular Sequence Data
Recombinant Proteins - chemistry
Recombinant Proteins - metabolism
sbsC gene
Sequence Analysis, DNA
Structure-Activity Relationship
title S-layer gene sbsC of Bacillus stearothermophilus ATCC 12980: molecular characterization and heterologous expression in Escherichia coli
url https://sfx.bib-bvb.de/sfx_tum?ctx_ver=Z39.88-2004&ctx_enc=info:ofi/enc:UTF-8&ctx_tim=2025-01-20T19%3A34%3A56IST&url_ver=Z39.88-2004&url_ctx_fmt=infofi/fmt:kev:mtx:ctx&rfr_id=info:sid/primo.exlibrisgroup.com:primo3-Article-proquest_pubme&rft_val_fmt=info:ofi/fmt:kev:mtx:journal&rft.genre=article&rft.atitle=S-layer%20gene%20sbsC%20of%20Bacillus%20stearothermophilus%20ATCC%2012980:%20molecular%20characterization%20and%20heterologous%20expression%20in%20Escherichia%20coli&rft.jtitle=Microbiology%20(Society%20for%20General%20Microbiology)&rft.au=Jarosch,%20Marina&rft.date=2000-02-01&rft.volume=146&rft.issue=2&rft.spage=273&rft.epage=281&rft.pages=273-281&rft.issn=1350-0872&rft.eissn=1465-2080&rft_id=info:doi/10.1099/00221287-146-2-273&rft_dat=%3Cproquest_pubme%3E17495500%3C/proquest_pubme%3E%3Curl%3E%3C/url%3E&disable_directlink=true&sfx.directlink=off&sfx.report_link=0&rft_id=info:oai/&rft_pqid=17495500&rft_id=info:pmid/10708365&rfr_iscdi=true