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
    One sequence, two ribozymes: implications for the emergence of new ribozyme folds (2000)
    American Association for the Advancement of Science (AAAS)
    Details
    Publication Date: 2000-07-21
    Description: We describe a single RNA sequence that can assume either of two ribozyme folds and catalyze the two respective reactions. The two ribozyme folds share no evolutionary history and are completely different, with no base pairs (and probably no hydrogen bonds) in common. Minor variants of this sequence are highly active for one or the other reaction, and can be accessed from prototype ribozymes through a series of neutral mutations. Thus, in the course of evolution, new RNA folds could arise from preexisting folds, without the need to carry inactive intermediate sequences. This raises the possibility that biological RNAs having no structural or functional similarity might share a common ancestry. Furthermore, functional and structural divergence might, in some cases, precede rather than follow gene duplication.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Schultes, E A -- Bartel, D P -- New York, N.Y. -- Science. 2000 Jul 21;289(5478):448-52.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Whitehead Institute for Biomedical Research and Department of Biology, Massachusetts Institute of Technology, 9 Cambridge Center, Cambridge, MA 02142, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/10903205" target="_blank"〉PubMed〈/a〉
    Keywords: Base Sequence ; Catalysis ; Evolution, Molecular ; Gene Duplication ; Hepatitis Delta Virus/enzymology/genetics ; Molecular Sequence Data ; Mutation ; Nucleic Acid Conformation ; Point Mutation ; RNA/metabolism ; RNA, Catalytic/*chemistry/genetics/*metabolism
    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
  • 2
    facet.materialart.
    Unknown
    RNA-catalyzed RNA polymerization: accurate and general RNA-templated primer extension (2001)
    American Association for the Advancement of Science (AAAS)
    Details
    Publication Date: 2001-05-19
    Description: The RNA world hypothesis regarding the early evolution of life relies on the premise that some RNA sequences can catalyze RNA replication. In support of this conjecture, we describe here an RNA molecule that catalyzes the type of polymerization needed for RNA replication. The ribozyme uses nucleoside triphosphates and the coding information of an RNA template to extend an RNA primer by the successive addition of up to 14 nucleotides-more than a complete turn of an RNA helix. Its polymerization activity is general in terms of the sequence and the length of the primer and template RNAs, provided that the 3' terminus of the primer pairs with the template. Its polymerization is also quite accurate: when primers extended by 11 nucleotides were cloned and sequenced, 1088 of 1100 sequenced nucleotides matched the template.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Johnston, W K -- Unrau, P J -- Lawrence, M S -- Glasner, M E -- Bartel, D P -- New York, N.Y. -- Science. 2001 May 18;292(5520):1319-25.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Whitehead Institute for Biomedical Research, and Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02142, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/11358999" target="_blank"〉PubMed〈/a〉
    Keywords: Base Sequence ; Conserved Sequence/genetics ; Directed Molecular Evolution ; Molecular Sequence Data ; Mutagenesis/genetics ; Nucleic Acid Conformation ; RNA/*biosynthesis/genetics ; RNA Replicase/chemistry/genetics/*metabolism ; RNA, Catalytic/chemistry/genetics/*metabolism ; Sequence Analysis, RNA ; Substrate Specificity ; Templates, Genetic
    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
  • 3
    facet.materialart.
    Unknown
    An abundant class of tiny RNAs with probable regulatory roles in Caenorhabditis elegans (2001)
    American Association for the Advancement of Science (AAAS)
    Details
    Publication Date: 2001-10-27
    Description: Two small temporal RNAs (stRNAs), lin-4 and let-7, control developmental timing in Caenorhabditis elegans. We find that these two regulatory RNAs are members of a large class of 21- to 24-nucleotide noncoding RNAs, called microRNAs (miRNAs). We report on 55 previously unknown miRNAs in C. elegans. The miRNAs have diverse expression patterns during development: a let-7 paralog is temporally coexpressed with let-7; miRNAs encoded in a single genomic cluster are coexpressed during embryogenesis; and still other miRNAs are expressed constitutively throughout development. Potential orthologs of several of these miRNA genes were identified in Drosophila and human genomes. The abundance of these tiny RNAs, their expression patterns, and their evolutionary conservation imply that, as a class, miRNAs have broad regulatory functions in animals.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Lau, N C -- Lim, L P -- Weinstein, E G -- Bartel, D P -- New York, N.Y. -- Science. 2001 Oct 26;294(5543):858-62.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Whitehead Institute for Biomedical Research, and Department of Biology, Massachusetts Institute of Technology, 9 Cambridge Center, Cambridge, MA 02142, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/11679671" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Base Sequence ; Blotting, Northern ; Caenorhabditis elegans/*genetics ; Cloning, Molecular ; Conserved Sequence ; Endoribonucleases/metabolism ; *Gene Expression Regulation ; Gene Expression Regulation, Developmental ; Genes, Helminth ; Genome ; Humans ; Molecular Sequence Data ; Multigene Family ; Nucleic Acid Conformation ; RNA Precursors/genetics/metabolism ; RNA, Helminth/*chemistry/*genetics/physiology ; RNA, Untranslated/chemistry/*genetics/physiology ; Ribonuclease III ; Transcription, Genetic
    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
    Crystal structure of the catalytic core of an RNA-polymerase ribozyme (2009)
    American Association for the Advancement of Science (AAAS)
    Details
    Publication Date: 2009-12-08
    Description: Primordial organisms of the putative RNA world would have required polymerase ribozymes able to replicate RNA. Known ribozymes with polymerase activity best approximating that needed for RNA replication contain at their catalytic core the class I RNA ligase, an artificial ribozyme with a catalytic rate among the fastest of known ribozymes. Here we present the 3.0 angstrom crystal structure of this ligase. The architecture resembles a tripod, its three legs converging near the ligation junction. Interacting with this tripod scaffold through a series of 10 minor-groove interactions (including two A-minor triads) is the unpaired segment that contributes to and organizes the active site. A cytosine nucleobase and two backbone phosphates abut the ligation junction; their location suggests a model for catalysis resembling that of proteinaceous polymerases.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3978776/" 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/PMC3978776/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Shechner, David M -- Grant, Robert A -- Bagby, Sarah C -- Koldobskaya, Yelena -- Piccirilli, Joseph A -- Bartel, David P -- GM61835/GM/NIGMS NIH HHS/ -- R01 GM061835/GM/NIGMS NIH HHS/ -- Howard Hughes Medical Institute/ -- New York, N.Y. -- Science. 2009 Nov 27;326(5957):1271-5. doi: 10.1126/science.1174676.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Whitehead Institute for Biomedical Research and Howard Hughes Medical Institute, 9 Cambridge Center, Cambridge, MA 02142, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/19965478" target="_blank"〉PubMed〈/a〉
    Keywords: Base Pairing ; Base Sequence ; Catalysis ; Catalytic Domain ; Crystallization ; Crystallography, X-Ray ; DNA-Directed RNA Polymerases/chemistry/metabolism ; Hydrogen Bonding ; Hydrogen-Ion Concentration ; Magnesium/chemistry/metabolism ; Models, Molecular ; Molecular Sequence Data ; Nucleic Acid Conformation ; Polynucleotide Ligases/chemistry/metabolism ; RNA, Catalytic/*chemistry/metabolism ; Ribonucleotides/chemistry/metabolism
    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
  • 5
    facet.materialart.
    Unknown
    MicroRNA-directed cleavage of HOXB8 mRNA (2004)
    American Association for the Advancement of Science (AAAS)
    Details
    Publication Date: 2004-04-24
    Description: MicroRNAs (miRNAs) are endogenous approximately 22-nucleotide RNAs, some of which are known to play important regulatory roles in animals by targeting the messages of protein-coding genes for translational repression. We find that miR-196, a miRNA encoded at three paralogous locations in the A, B, and C mammalian HOX clusters, has extensive, evolutionarily conserved complementarity to messages of HOXB8, HOXC8, and HOXD8. RNA fragments diagnostic of miR-196-directed cleavage of HOXB8 were detected in mouse embryos. Cell culture experiments demonstrated down-regulation of HOXB8, HOXC8, HOXD8, and HOXA7 and supported the cleavage mechanism for miR-196-directed repression of HOXB8. These results point to a miRNA-mediated mechanism for the posttranscriptional restriction of HOX gene expression during vertebrate development and demonstrate that metazoan miRNAs can repress expression of their natural targets through mRNA cleavage in addition to inhibiting productive translation.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Yekta, Soraya -- Shih, I-Hung -- Bartel, David P -- New York, N.Y. -- Science. 2004 Apr 23;304(5670):594-6.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Whitehead Institute for Biomedical Research, Nine Cambridge Center, Cambridge, MA 02142, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/15105502" target="_blank"〉PubMed〈/a〉
    Keywords: 3' Untranslated Regions ; Animals ; Base Sequence ; Down-Regulation ; *Genes, Homeobox ; Genes, Reporter ; HeLa Cells ; Homeodomain Proteins/*genetics ; Humans ; Mice ; MicroRNAs/chemistry/genetics/*metabolism ; Molecular Sequence Data ; Neoplasm Proteins/genetics ; RNA, Messenger/chemistry/*genetics/*metabolism ; Sequence Alignment ; Transcription Factors/genetics ; Transfection
    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
  • 6
    facet.materialart.
    Unknown
    The widespread impact of mammalian MicroRNAs on mRNA repression and evolution (2005)
    American Association for the Advancement of Science (AAAS)
    Details
    Publication Date: 2005-11-26
    Description: Thousands of mammalian messenger RNAs are under selective pressure to maintain 7-nucleotide sites matching microRNAs (miRNAs). We found that these conserved targets are often highly expressed at developmental stages before miRNA expression and that their levels tend to fall as the miRNA that targets them begins to accumulate. Nonconserved sites, which outnumber the conserved sites 10 to 1, also mediate repression. As a consequence, genes preferentially expressed at the same time and place as a miRNA have evolved to selectively avoid sites matching the miRNA. This phenomenon of selective avoidance extends to thousands of genes and enables spatial and temporal specificities of miRNAs to be revealed by finding tissues and developmental stages in which messages with corresponding sites are expressed at lower levels.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Farh, Kyle Kai-How -- Grimson, Andrew -- Jan, Calvin -- Lewis, Benjamin P -- Johnston, Wendy K -- Lim, Lee P -- Burge, Christopher B -- Bartel, David P -- New York, N.Y. -- Science. 2005 Dec 16;310(5755):1817-21. Epub 2005 Nov 24.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Whitehead Institute for Biomedical Research, Department of Biology, Massachusetts Institute of Technology, and Howard Hughes Medical Institute, 9 Cambridge Center, Cambridge, MA 02142, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/16308420" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Base Sequence ; Cell Differentiation ; Conserved Sequence ; *Evolution, Molecular ; Gene Expression Profiling ; *Gene Expression Regulation ; Humans ; Mammals/*genetics ; Mice ; MicroRNAs/*metabolism ; Molecular Sequence Data ; Muscle Fibers, Skeletal/cytology/metabolism ; Organ Specificity ; RNA Stability ; RNA, Messenger/*genetics/metabolism ; Rats ; Species Specificity ; Untranslated Regions ; Zebrafish/genetics
    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
  • 7
    facet.materialart.
    Unknown
    Structure of yeast Argonaute with guide RNA (2012)
    Nature Publishing Group (NPG)
    Details
    Publication Date: 2012-06-23
    Description: The RNA-induced silencing complex, comprising Argonaute and guide RNA, mediates RNA interference. Here we report the 3.2 A crystal structure of Kluyveromyces polysporus Argonaute (KpAGO) fortuitously complexed with guide RNA originating from small-RNA duplexes autonomously loaded by recombinant KpAGO. Despite their diverse sequences, guide-RNA nucleotides 1-8 are positioned similarly, with sequence-independent contacts to bases, phosphates and 2'-hydroxyl groups pre-organizing the backbone of nucleotides 2-8 in a near-A-form conformation. Compared with prokaryotic Argonautes, KpAGO has numerous surface-exposed insertion segments, with a cluster of conserved insertions repositioning the N domain to enable full propagation of guide-target pairing. Compared with Argonautes in inactive conformations, KpAGO has a hydrogen-bond network that stabilizes an expanded and repositioned loop, which inserts an invariant glutamate into the catalytic pocket. Mutation analyses and analogies to ribonuclease H indicate that insertion of this glutamate finger completes a universally conserved catalytic tetrad, thereby activating Argonaute for RNA cleavage.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3853139/" 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/PMC3853139/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Nakanishi, Kotaro -- Weinberg, David E -- Bartel, David P -- Patel, Dinshaw J -- AI068776/AI/NIAID NIH HHS/ -- GM61835/GM/NIGMS NIH HHS/ -- R01 AI068776/AI/NIAID NIH HHS/ -- R01 GM061835/GM/NIGMS NIH HHS/ -- R37 GM061835/GM/NIGMS NIH HHS/ -- Howard Hughes Medical Institute/ -- England -- Nature. 2012 Jun 20;486(7403):368-74. doi: 10.1038/nature11211.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Structural Biology Program, Memorial Sloan-Kettering Cancer Center, New York, New York 10065, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/22722195" target="_blank"〉PubMed〈/a〉
    Keywords: Argonaute Proteins/*chemistry/*metabolism ; Base Sequence ; Biocatalysis ; Catalytic Domain ; Crystallography, X-Ray ; Eukaryotic Cells/chemistry/enzymology ; Fungal Proteins/*chemistry/*metabolism ; Kluyveromyces/*chemistry/enzymology ; Models, Molecular ; Molecular Conformation ; Molecular Sequence Data ; RNA, Guide/*chemistry/genetics/*metabolism ; Saccharomycetales/enzymology/genetics
    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
  • 8
    facet.materialart.
    Unknown
    Isolation of new ribozymes from a large pool of random sequences [see comment] (1993)
    American Association for the Advancement of Science (AAAS)
    Details
    Publication Date: 1993-09-10
    Description: An iterative in vitro selection procedure was used to isolate a new class of catalytic RNAs (ribozymes) from a large pool of random-sequence RNA molecules. These ribozymes ligate two RNA molecules that are aligned on a template by catalyzing the attack of a 3'-hydroxyl on an adjacent 5'-triphosphate--a reaction similar to that employed by the familiar protein enzymes that synthesize RNA. The corresponding uncatalyzed reaction also yields a 3',5'-phosphodiester bond. In vitro evolution of the population of new ribozymes led to improvement of the average ligation activity and the emergence of ribozymes with reaction rates 7 million times faster than the uncatalyzed reaction rate.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Bartel, D P -- Szostak, J W -- New York, N.Y. -- Science. 1993 Sep 10;261(5127):1411-8.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Molecular Biology, Massachusetts General Hospital, Boston 02114.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/7690155" target="_blank"〉PubMed〈/a〉
    Keywords: Base Sequence ; Biological Evolution ; Catalysis ; Kinetics ; Magnesium/metabolism ; Molecular Sequence Data ; Mutation ; Oligoribonucleotides/metabolism ; RNA/*metabolism ; RNA Ligase (ATP)/chemistry/isolation & purification/metabolism ; RNA, Catalytic/chemistry/*isolation & purification/metabolism ; Temperature ; Templates, Genetic
    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
  • 9
    facet.materialart.
    Unknown
    Structurally complex and highly active RNA ligases derived from random RNA sequences (1995)
    American Association for the Advancement of Science (AAAS)
    Details
    Publication Date: 1995-07-21
    Description: Seven families of RNA ligases, previously isolated from random RNA sequences, fall into three classes on the basis of secondary structure and regiospecificity of ligation. Two of the three classes of ribozymes have been engineered to act as true enzymes, catalyzing the multiple-turnover transformation of substrates into products. The most complex of these ribozymes has a minimal catalytic domain of 93 nucleotides. An optimized version of this ribozyme has a kcat exceeding one per second, a value far greater than that of most natural RNA catalysts and approaching that of comparable protein enzymes. The fact that such a large and complex ligase emerged from a very limited sampling of sequence space implies the existence of a large number of distinct RNA structures of equivalent complexity and activity.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Ekland, E H -- Szostak, J W -- Bartel, D P -- New York, N.Y. -- Science. 1995 Jul 21;269(5222):364-70.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/7618102" target="_blank"〉PubMed〈/a〉
    Keywords: Base Sequence ; Catalysis ; Cloning, Molecular ; Conserved Sequence ; Introns ; Molecular Sequence Data ; Mutagenesis ; *Nucleic Acid Conformation ; Point Mutation ; RNA, Catalytic/*chemistry/classification/*metabolism ; Sequence Deletion
    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
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...