ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    facet.materialart.
    Unknown
    Structures of the RNA-guided surveillance complex from a bacterial immune system (2011)
    Nature Publishing Group (NPG)
    Details
    Publication Date: 2011-09-23
    Description: Bacteria and archaea acquire resistance to viruses and plasmids by integrating short fragments of foreign DNA into clustered regularly interspaced short palindromic repeats (CRISPRs). These repetitive loci maintain a genetic record of all prior encounters with foreign transgressors. CRISPRs are transcribed and the long primary transcript is processed into a library of short CRISPR-derived RNAs (crRNAs) that contain a unique sequence complementary to a foreign nucleic-acid challenger. In Escherichia coli, crRNAs are incorporated into a multisubunit surveillance complex called Cascade (CRISPR-associated complex for antiviral defence), which is required for protection against bacteriophages. Here we use cryo-electron microscopy to determine the subnanometre structures of Cascade before and after binding to a target sequence. These structures reveal a sea-horse-shaped architecture in which the crRNA is displayed along a helical arrangement of protein subunits that protect the crRNA from degradation while maintaining its availability for base pairing. Cascade engages invading nucleic acids through high-affinity base-pairing interactions near the 5' end of the crRNA. Base pairing extends along the crRNA, resulting in a series of short helical segments that trigger a concerted conformational change. This conformational rearrangement may serve as a signal that recruits a trans-acting nuclease (Cas3) for destruction of invading nucleic-acid sequences.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4165517/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉   〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4165517/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Wiedenheft, Blake -- Lander, Gabriel C -- Zhou, Kaihong -- Jore, Matthijs M -- Brouns, Stan J J -- van der Oost, John -- Doudna, Jennifer A -- Nogales, Eva -- Howard Hughes Medical Institute/ -- England -- Nature. 2011 Sep 21;477(7365):486-9. doi: 10.1038/nature10402.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Howard Hughes Medical Institute, University of California, Berkeley, California 94720, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/21938068" target="_blank"〉PubMed〈/a〉
    Keywords: Base Pairing ; Cryoelectron Microscopy ; Escherichia coli K12/chemistry/*genetics/*immunology/virology ; Escherichia coli Proteins/chemistry/immunology/*ultrastructure ; Inverted Repeat Sequences/genetics/immunology ; Macromolecular Substances/*chemistry/metabolism/*ultrastructure ; Models, Biological ; Models, Molecular ; Protein Conformation ; RNA, Bacterial/genetics/*immunology/*ultrastructure
    Print ISSN: 0028-0836
    Electronic ISSN: 1476-4687
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Published by Nature Publishing Group (NPG)
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 2
    facet.materialart.
    Unknown
    DNA-guided DNA interference by a prokaryotic Argonaute (2014)
    Nature Publishing Group (NPG)
    Details
    Publication Date: 2014-02-18
    Description: RNA interference is widely distributed in eukaryotes and has a variety of functions, including antiviral defence and gene regulation. All RNA interference pathways use small single-stranded RNA (ssRNA) molecules that guide proteins of the Argonaute (Ago) family to complementary ssRNA targets: RNA-guided RNA interference. The role of prokaryotic Ago variants has remained elusive, although bioinformatics analysis has suggested their involvement in host defence. Here we demonstrate that Ago of the bacterium Thermus thermophilus (TtAgo) acts as a barrier for the uptake and propagation of foreign DNA. In vivo, TtAgo is loaded with 5'-phosphorylated DNA guides, 13-25 nucleotides in length, that are mostly plasmid derived and have a strong bias for a 5'-end deoxycytidine. These small interfering DNAs guide TtAgo to cleave complementary DNA strands. Hence, despite structural homology to its eukaryotic counterparts, TtAgo functions in host defence by DNA-guided DNA interference.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4697943/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉   〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4697943/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Swarts, Daan C -- Jore, Matthijs M -- Westra, Edze R -- Zhu, Yifan -- Janssen, Jorijn H -- Snijders, Ambrosius P -- Wang, Yanli -- Patel, Dinshaw J -- Berenguer, Jose -- Brouns, Stan J J -- van der Oost, John -- P30 CA008748/CA/NCI NIH HHS/ -- R01 GM104962/GM/NIGMS NIH HHS/ -- England -- Nature. 2014 Mar 13;507(7491):258-61. doi: 10.1038/nature12971. Epub 2014 Feb 16.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉1] Laboratory of Microbiology, Department of Agrotechnology and Food Sciences, Wageningen University, Dreijenplein 10, 6703 HB Wageningen, the Netherlands [2]. ; Laboratory of Microbiology, Department of Agrotechnology and Food Sciences, Wageningen University, Dreijenplein 10, 6703 HB Wageningen, the Netherlands. ; Clare Hall Laboratories, Cancer Research UK, London Research Institute, South Mimms EN6 3LD, UK. ; Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China. ; Structural Biology Program, Memorial Sloan-Kettering Cancer Center, New York, New York 10065, USA. ; Centro de Biologia Molecular Severo Ochoa, UAM-CSIC, Campus de Cantoblanco, 28049 Madrid, Spain.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/24531762" target="_blank"〉PubMed〈/a〉
    Keywords: Argonaute Proteins/*metabolism ; Base Pairing/genetics ; Base Sequence ; DNA/genetics/*metabolism ; *DNA Cleavage ; Deoxycytidine/genetics/metabolism ; *Gene Silencing ; Phosphorylation ; Plasmids/genetics ; Prokaryotic Cells/*metabolism ; Thermus thermophilus/*genetics/*metabolism
    Print ISSN: 0028-0836
    Electronic ISSN: 1476-4687
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Published by Nature Publishing Group (NPG)
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 3
    facet.materialart.
    Unknown
    Small CRISPR RNAs guide antiviral defense in prokaryotes (2008)
    American Association for the Advancement of Science (AAAS)
    Details
    Publication Date: 2008-08-16
    Description: Prokaryotes acquire virus resistance by integrating short fragments of viral nucleic acid into clusters of regularly interspaced short palindromic repeats (CRISPRs). Here we show how virus-derived sequences contained in CRISPRs are used by CRISPR-associated (Cas) proteins from the host to mediate an antiviral response that counteracts infection. After transcription of the CRISPR, a complex of Cas proteins termed Cascade cleaves a CRISPR RNA precursor in each repeat and retains the cleavage products containing the virus-derived sequence. Assisted by the helicase Cas3, these mature CRISPR RNAs then serve as small guide RNAs that enable Cascade to interfere with virus proliferation. Our results demonstrate that the formation of mature guide RNAs by the CRISPR RNA endonuclease subunit of Cascade is a mechanistic requirement for antiviral defense.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Brouns, Stan J J -- Jore, Matthijs M -- Lundgren, Magnus -- Westra, Edze R -- Slijkhuis, Rik J H -- Snijders, Ambrosius P L -- Dickman, Mark J -- Makarova, Kira S -- Koonin, Eugene V -- van der Oost, John -- New York, N.Y. -- Science. 2008 Aug 15;321(5891):960-4. doi: 10.1126/science.1159689.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Laboratory of Microbiology, Department of Agrotechnology and Food Sciences, Wageningen University, Dreijenplein 10, 6703 HB Wageningen, Netherlands.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/18703739" target="_blank"〉PubMed〈/a〉
    Keywords: Amino Acid Sequence ; Bacteriophage lambda/*genetics/*growth & development ; Base Sequence ; DNA, Intergenic ; DNA, Viral/metabolism ; Escherichia coli/genetics/metabolism ; Escherichia coli K12/*genetics/metabolism/*virology ; Escherichia coli Proteins/chemistry/genetics/*metabolism ; Genes, Bacterial ; Molecular Sequence Data ; RNA Precursors/metabolism ; RNA, Bacterial/*genetics/metabolism ; RNA, Guide/genetics/metabolism ; *Repetitive Sequences, Nucleic Acid ; Transcription, Genetic ; Viral Plaque Assay
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Published by American Association for the Advancement of Science (AAAS)
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 4
    facet.materialart.
    Unknown
    Interference by clustered regularly interspaced short palindromic repeat (CRISPR) RNA is governed by a seed sequence (2011)
    National Academy of Sciences
    Details
    Publication Date: 2011-06-06
    Print ISSN: 0027-8424
    Electronic ISSN: 1091-6490
    Topics: Biology , Medicine , Natural Sciences in General
    Published by National Academy of Sciences
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 5
    facet.materialart.
    Unknown
    Interference by clustered regularly interspaced short palindromic repeat (CRISPR) RNA is governed by a seed sequence [Biochemistry] (2011)
    National Academy of Sciences
    Details
    Publication Date: 2011-06-22
    Description: Prokaryotic clustered regularly interspaced short palindromic repeat (CRISPR)/Cas (CRISPR-associated sequences) systems provide adaptive immunity against viruses when a spacer sequence of small CRISPR RNA (crRNA) matches a protospacer sequence in the viral genome. Viruses that escape CRISPR/Cas resistance carry point mutations in protospacers, though not all protospacer mutations lead to escape. Here, we show that in the case of Escherichia coli subtype CRISPR/Cas system, the requirements for crRNA matching are strict only for a seven-nucleotide seed region of a protospacer immediately following the essential protospacer-adjacent motif. Mutations in the seed region abolish CRISPR/Cas mediated immunity by reducing the binding affinity of the crRNA-guided Cascade complex to protospacer DNA. We propose that the crRNA seed sequence plays a role in the initial scanning of invader DNA for a match, before base pairing of the full-length spacer occurs, which may enhance the protospacer locating efficiency of the E. coli Cascade complex. In agreement with this proposal, single or multiple mutations within the protospacer but outside the seed region do not lead to escape. The relaxed specificity of the CRISPR/Cas system limits escape possibilities and allows a single crRNA to effectively target numerous related viruses.
    Print ISSN: 0027-8424
    Electronic ISSN: 1091-6490
    Topics: Biology , Medicine , Natural Sciences in General
    Published by National Academy of Sciences
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...