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161.
Interest in the characterisation of O-mannosyl glycan structures has been stimulated following the identification of mannitol-terminating oligosaccharides among the chains released from mammalian proteins in nervous and muscle tissues, and by the discovery of a putative human O-mannosyl transferase. Several mass spectrometry methods have been applied to structure elucidation particularly when low amounts of oligosaccharide are available for analysis. However, when sufficient amounts are available, a combination of through-bond homo- and heteronuclear, and of through-space homonuclear NMR experiments permit the complete identification of these oligosaccharide sequences. We describe here the assignment of 1H and 13C NMR chemical shifts from such experiments for four mannitol-terminating oligosaccharide alditols, GlcNAcbeta-(1-->2)Manol, Galbeta-(1-->4)GlcNAcbeta-(1-->2)Manol, Galbeta-(1-->4)[Fucalpha-(1-->3)]GlcNAcbeta-(1-->2)Manol and NeuAcalpha-(2-->3)Galbeta-(1-->4)GlcNAcbeta-(1-->2)Manol, that were released from brain glycopeptides by alkaline borohydride treatment. 相似文献
162.
Faithful segregation of sister chromatids during cell division requires properly regulated cohesion between the sister centromeres.
The sister chromatids are attached along their lengths, but particularly tightly in the centromeric regions. Therefore specific
cohesion proteins may be needed at the centromere. Here we show that Drosophila MEI-S332 protein localizes to mitotic metaphase centromeres. Both overexpression and mutation of MEI-S332 increase the number
of apoptotic cells. In mei-S332 mutants the ratio of metaphase to anaphase figures is lower than wild type, but it is higher if MEI-S332 is overexpressed.
In chromosomal squashes centromeric attachments appear weaker in mei-S332 mutants than wild type and tighter when MEI-S332 is overexpressed. These results are consistent with MEI-S332 contributing
to centromeric sister-chromatid cohesion in a dose-dependent manner. MEI-S332 is the first member identified of a predicted
class of centromeric proteins that maintain centromeric cohesion.
Received: 11 December 1998; in revised form: 4 August 1999 / Accepted: 13 August 1999 相似文献
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PathoGene is a web-based resource that streamlines the process of predicting genes in microorganisms and designs PCR primers for amplification to facilitate sequence analysis and experimentation. PathoGene currently supports primer design for every complete microbial, viral, and fungal genome as cataloged in GenBank by the National Center for Biotechnology Information (NCBI; http://www.ncbi.nlm.nih.gov/). The resulting primers can then be subjected to a stand-alone Basic Local Alignment Search Tool (BLAST) system called PathoBLAST in which the predicted PCR product and/or primers can be compared against the genome of interest or a similar genome to find related genes or estimate primer quality. 相似文献
166.
Lewis RA Kress TL Cote CA Gautreau D Rokop ME Mowry KL 《Mechanisms of development》2004,121(1):101-109
Although it is widely regarded that the targeting of RNA molecules to subcellular destinations depends upon the recognition of cis-elements found within their 3' untranslated regions (UTR), relatively little is known about the specific features of these cis-sequences that underlie their function. Interaction between specific repeated motifs within the 3' UTR and RNA-binding proteins has been proposed as a critical step in the localization of Vg1 RNA to the vegetal pole of Xenopus oocytes. To understand the relative contributions of repeated localization element (LE) sequences, we used comparative functional analysis of Vg1 LEs from two frog species, Xenopus laevis and Xenopus borealis. We show that clusters of repeated VM1 and E2 motifs are required for efficient localization. However, groups of either site alone are not sufficient for localization. In addition, we present evidence that the X. borealis Vg1 LE is recognized by the same set of RNA-binding proteins as the X. laevis Vg1 LE and is capable of productive interactions with the X. laevis transport machinery as it is sufficient to direct vegetal localization in X. laevis oocytes. These results suggest that clustered sets of cis-acting sites within the LE direct vegetal transport through specific interactions with the localization machinery. 相似文献
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Christopher?A?BidwellEmail author Lauren?N?Kramer Allison?C?Perkins Tracy?S?Hadfield Diane?E?Moody Noelle?E?Cockett 《BMC biology》2004,2(1):17