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Shock Domain (shock + domain)

Distribution by Scientific Domains
Life Sciences100%

Kinds of Shock Domain

  • cold shock domain
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    Selected Abstracts

    Comparative analysis of changes in gene expression due to RNA melting activities of translation initiation factor IF1 and a cold shock protein of the CspA family

    GENES TO CELLS, Issue 11 2009
    Sangita Phadtare
    In Escherichia coli, temperature downshift elicits cold shock response, which is characterized by induction of cold shock proteins. CspA, the major cold shock protein of E. coli, helps cells to acclimatize to low temperature by melting the secondary structures in nucleic acids and acting as a transcription antiterminator. CspA and its homologues contain the cold shock domain and belong to the oligomer binding protein family, which also includes S1 domain proteins such as IF1. Structural similarity between IF1 and CspA homologues suggested a functional overlap between these proteins. Indeed IF1 can melt secondary structures in RNA and acts as transcription antiterminator in vivo and in vitro. Here, we show that in spite of having these critical activities, IF1 does not complement cold-sensitivity of a csp quadruple deletion strain. DNA microarray analysis shows that overproduction of IF1 and Csp leads to changes in expression of different sets of genes. Importantly, several genes which were previously shown to require Csp proteins for their expression at low temperature did not respond to IF1. Moreover, in vitro, we show that a transcription terminator responsive to Csp does not respond to IF1. Our results suggest that Csp proteins and IF1 have different sets of target genes as they may be suppressing the function of different types of transcription termination elements in specific genes. [source]

    Nuclease sensitive element binding protein 1 gene disruption results in early embryonic lethality

    JOURNAL OF CELLULAR BIOCHEMISTRY, Issue 1 2006
    Lin Fan
    Abstract Nuclease sensitive element binding protein 1 (NSEP1) is a member of the EFIA/NSEP1/YB-1 family of DNA-binding proteins whose members share a cold shock domain; it has also been termed DNA-binding protein B and Y box binding protein-1 because of its recognition of transcriptional regulatory elements. In addition, NSEP1 functions in the translational regulation of renin, ferritin, and interleukin 2 transcripts, and our laboratory has reported that it plays a role in the biosynthesis of selenium-containing proteins. To test the functional importance of NSEP1 in murine embryonic development, we have utilized a clone of ES cells in which the NSEP1 gene had been disrupted by integration of a plasmid gene-trapping vector into the seventh exon. Injection of these cells into C57BL/6 blastocysts resulted in 11 high percentage chimeric mice; crosses to wild type C57BL/6 mice generated 82 F1 agouti mice, indicating germ line transmission of the ES cell clone, but genotyping showed no evidence of the disrupted allele in any of these agouti offspring even though spermatozoa from four of five tested mice contained the targeted allele. Embryos harvested after timed matings of chimeric male mice demonstrated only the wildtype allele in 27 embryos tested at E7.5, E12.5, and E18.5. These results suggest that gene targeting of NSEP1 induces a lethal phenotype in early embryos, due to either haploinsufficiency of NSEP1 or formation of a dominant negative form of the protein. In either case, these data indicate the functional importance of the NSEP1 gene in murine early embryonic development. J. Cell. Biochem. © 2006 Wiley-Liss, Inc. [source]

    Acquisition of double-stranded DNA-binding ability in a hybrid protein between Escherichia coli CspA and the cold shock domain of human YB-1

    MOLECULAR MICROBIOLOGY, Issue 3 2000
    Nan Wang
    Escherichia coli CspA, a major cold shock protein, is dramatically induced upon temperature downshift. As it binds co-operatively to single-stranded DNA (ssDNA) and RNA without apparent sequence specificity, it has been proposed that CspA acts as an RNA chaperone to facilitate transcription and translation at low temperature. CspA consists of a five-stranded ,-barrel structure containing two RNA-binding motifs, RNP1 and RNP2. Eukaryotic Y-box proteins, such as human YB-1, are a family of nucleic acid-binding proteins that share a region of high homology with CspA (43% identity), termed the cold shock domain (CSD). Their cellular functions are very diverse and are associated with growth-related processes. Here, we replaced the six-residue loop region of CspA between the ,3 and ,4 strands with the corresponding region of the CSD of human YB-1 protein. The resulting hybrid protein became capable of binding to double-stranded DNA (dsDNA) in addition to ssDNA and RNA. The dsDNA-binding ability of an RNP1 point mutant (F20L) of the hybrid was almost unchanged. On the other hand, the dsDNA-binding ability of the hybrid protein was abolished in high salt concentrations in contrast to its ssDNA-binding ability. These results indicate that the loop region between the ,3 and ,4 strands of Y-box proteins, which is a little longer and more basic than that of CspA, plays an important role in their binding to dsDNA. [source]