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121.
The molecular biology of plant acclimation to low temperature 总被引:51,自引:8,他引:43
122.
Dianna M. Milewicz Peter H. Byers John Reveille Austin L. Hughes Madeleine Duvic 《Journal of molecular evolution》1996,42(2):117-123
Alu elements are a class of repetitive DNA sequences found throughout the human genome that are thought to be duplicated via an RNA intermediate in a process termed retroposition. Recently inserted Alu elements are closely related, suggesting that they are derived from a single source gene or closely related source genes. Analysis of the type III collagen gene (COL3A1) revealed a polymorphic Alu insertion in intron 8 of the gene. The Alu insertion in the COL3A1 gene had a high degree of nucleotide identity to the Sb family of Alu elements, a family of older Alu elements. The Alu sequence was less similar to the consensus sequence for the PV or Sb2 subfamilies, subfamilies of recently inserted Alu elements. These data support the observations that at least three source genes are active in the human genome, one of which is distinct from the PV and Sb2 subfamilies and predates either of these two subfamilies. Appearance of the Alu insertion in different ethnic populations suggests that the insertion may have occurred in the last 100,000 years. This Alu insert should be a useful marker for population studies and for marking COL3A1 alleles. 相似文献
123.
Inhibition of human immunodeficiency virus type 1 integrase by the Fab fragment of a specific monoclonal antibody suggests that different multimerization states are required for different enzymatic functions. 下载免费PDF全文
E V Barsov W E Huber J Marcotrigiano P K Clark A D Clark E Arnold S H Hughes 《Journal of virology》1996,70(7):4484-4494
We have characterized a murine monoclonal antibody (MAb 35), which was raised against human immunodeficiency virus type 1 (HIV-1) integration protein (IN), and the corresponding Fab 35. Although MAb 35 does not inhibit HIV-1 IN, Fab 35 does. MAb 35 (and Fab 35) binds to an epitope in the C-terminal region of HIV-1 IN. Fab 35 inhibits 3'-end processing, strand transfer, and disintegration; however, DNA binding is not affected. The available data suggest that Fab 35 inhibits enzymatic activities of IN by interfering with the ability of IN to form multimers that are enzymatically active. This implies that the C-terminal region of HIV-1 IN participates in interactions that are essential for the multimerization of IN. Titration of the various IN-mediated enzymatic activities suggests that different degrees of multimerization are required for different activities of HIV-1 IN. 相似文献
124.
125.
The SWISS-2DPAGE database of two-dimensional polyacrylamide gel electrophoresis, its status in 1995. 总被引:1,自引:0,他引:1 下载免费PDF全文
R D Appel J C Sanchez A Bairoch O Golaz F Ravier C Pasquali G J Hughes D F Hochstrasser 《Nucleic acids research》1996,24(1):180-181
SWISS-2DPAGE is a database of proteins identified on two-dimensional polyacrylamide gel electrophoresis (2-D PAGE). The current release contains 343 entries of human, yeast (Saccharomyces cerevisiae) and Escherichia coli origin, as well as virtual entries for each of the protein sequences in the SWISS-PROT database. 相似文献
126.
Excess amino acid polymorphism in mitochondrial DNA: contrasts among genes from Drosophila, mice, and humans 总被引:13,自引:3,他引:10
Recent studies of mitochondrial DNA (mtDNA) variation in mammals and
Drosophila have shown an excess of amino acid variation within species
(replacement polymorphism) relative to the number of silent and replacement
differences fixed between species. To examine further this pattern of
nonneutral mtDNA evolution, we present sequence data for the ND3 and ND5
genes from 59 lines of Drosophila melanogaster and 29 lines of D. simulans.
Of interest are the frequency spectra of silent and replacement
polymorphisms, and potential variation among genes and taxa in the
departures from neutral expectations. The Drosophila ND3 and ND5 data show
no significant excess of replacement polymorphism using the
McDonald-Kreitman test. These data are in contrast to significant
departures from neutrality for the ND3 gene in mammals and other genes in
Drosophila mtDNA (cytochrome b and ATPase 6). Pooled across genes, however,
both Drosophila and human mtDNA show very significant excesses of amino
acid polymorphism. Silent polymorphisms at ND5 show a significantly higher
variance in frequency than replacement polymorphisms, and the latter show a
significant skew toward low frequencies (Tajima's D = -1.954). These
patterns are interpreted in light of the nearly neutral theory where mildly
deleterious amino acid haplotypes are observed as ephemeral variants within
species but do not contribute to divergence. The patterns of polymorphism
and divergence at charge-altering amino acid sites are presented for the
Drosophila ND5 gene to examine the evolution of functionally distinct
mutations. Excess charge-altering polymorphism is observed at the carboxyl
terminal and excess charge-altering divergence is detected at the amino
terminal. While the mildly deleterious model fits as a net effect in the
evolution of nonrecombining mitochondrial genomes, these data suggest that
opposing evolutionary pressures may act on different regions of
mitochondrial genes and genomes.
相似文献
127.
J. M. R. Hughes 《Plant Ecology》1995,118(1-2):17-28
The status of wetland inventory and classification is considered for 44 European countries, as well as for the continent as a whole. Data and information were obtained from questionnaires compiled by the International Waterfowl and Wetland Research Bureau, the MedWet sub-project on inventory and monitoring, and the Ramsar Bureau. Nine European countries have national wetland inventories, and 32 have inventories of sites of international importance listed under the Ramsar Convention. There has been a trend in producing regional or continental inventories for wetlands that are important as waterfowl habitat. There is an urgent need to produce wetland inventories for all European countries. The Ramsar database takes into consideration hydrological and economic wetland values, as well as ecological ones. The Ramsar classification lists a total of 35 wetland types, and is sufficiently flexible that it could be used for classifying European wetlands at the national scale. 相似文献
128.
A lectin preparation obtained fromTetracarpidium conophorum (Nigerian walnut) by affinity chromatography of seed extracts on lactose-agarose has been shown to contain two components by gel filtration on Sephadex G150. The larger componentTetracarpidium conophorum agglutinin I (TCAI) is a disulphide-bonded 70 kDa homodimer whereas the second component TCAII is a 34 kDa monomeric protein. Amino terminal aminoacid sequencing shows identity in TCAI and TCAII for the first fifteen residues after which the sequences diverge. TheN-terminal sequences of TCAI and TCAII show identity with sequences in the B-chains of ricin andRicinus communis agglutinin I (RCAI) in eleven of the initial fifteen residues. Thereafter TCAI appears to be homologous to the ricin B chain whereas TCAII is more homologous with the B chain of RCAI. A limited screening of the carbohydrate-binding specificity of TCAII by affinity chromatography of defined oligosaccharides on TCAII Sepharose columns shows that the binding specificity reported earlier for affinity purifiedTetracarpidium conophorum isolectins (Sato S, Animashaun T, Hughes RC (1991)J Biol Chem
266:11485–94) reflects the binding properties of TCAII which is the major isolectin in unfractionated lectin preparations. 相似文献
129.
We have characterized binding activities in yeast which recognise the T-rich strand of the yeast ARS consensus element and have purified two of these to homogeneity. One (ACBP-60) is detectable in both nuclear and whole cell extracts, while the other (ACBP-67) is apparent only after fractionation of extracts by heparin-sepharose chromatography. The major binding activity detected in nuclear extracts was purified on a sequence-specific DNA affinity column as a single polypeptide with apparent mobility of 60kDa (ACBP-60). This protein co-fractionates with nuclei, is present at several thousand copies per cell and has a Kd for the T-rich single strand of the ARS consensus between 10(-9) and 10(-10) M. Competition studies with simple nucleic acid polymers show that ACBP-60 has marginally higher affinity for poly dT30 than for a 30 nt oligomer containing the T-rich strand of ARS 307, and approximately 10 fold higher affinity for poly rU. Internal sequence information of purified p60 reveals identity with the open reading frames of genes PUB1 and RNP1 which encode polyuridylate binding protein(s). The second binding activity, ACBP-67, also binds specifically to the T-rich single strand of the ARS consensus, but with considerably lower affinity than ACBP-60. Peptide sequence reveals that the 67kDa protein is identical to the major polyA binding protein in yeast, PAB1. 相似文献
130.
Fine mapping of the Autosomal Dominant Split Hand/Split Foot Locus on Chromosome 7, Band q21.3-q22.1 总被引:6,自引:3,他引:3 下载免费PDF全文
Stephen W. Scherer Parvoneh Poorkaj Todd Allen Julia Kim Dorrit Geshuri Mark Nunes Sylvia Soder Karen Stephens Roberta A. Pagon Michael A. Patton Mary Anne Berg Tim Donlon Horacio Rivera R. A. Pfeiffer Kenji Naritomi Helen Hughes Maurizio Genuardi Fiorella Gurrieri Giovanni Neri Everett Lovrein Ellen Magenis Lap-Chee Tsui James P. Evans 《American journal of human genetics》1994,55(1):12-20
Split hand/split foot (SHFD) is a human developmental defect characterized by missing digits, fusion of remaining digits, and a deep median cleft in the hands and feet. Cytogenetic studies of deletions and translocations associated with this disorder have indicated that an autosomal dominant split hand/split foot locus (gene SHFD1) maps to 7q21-q22. To characterize the SHFD1 locus, somatic cell hybrid lines were constructed from cytogenetically abnormal individuals with SHFD. Molecular analysis resulted in the localization of 93 DNA markers to one of 10 intervals surrounding the SHFD1 locus. The translocation breakpoints in four SHFD patients were encompassed by the smallest region of overlap among the SHFD-associated deletions. The order of DNA markers in the SHFD1 critical region has been defined as PON–D7S812–SHFD1–D7S811–ASNS. One DNA marker, D7S811, detected altered restriction enzyme fragments in three patients with translocations when examined by pulsed-field gel electro-phoresis (PFGE). These data map SHFD1, a gene that is crucial for human limb differentiation, to a small interval in the q21.3-q22.1 region of human chromosome 7. 相似文献