Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.30.2 (endonuclease)
 18,621 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have isolated and characterized by restriction endonuclease mapping, transcription pattern, and DNA sequencing a beta-tubulin gene from the coenocytic freshwater protoctist, Achlya klebsiana. The gene is intronless and has a single open reading frame that encodes a 444-amino acid residue polypeptide of Mr 49,856. The protein shows a high degree of homology to other beta-tubulins, 85% identity to human beta-tubulin and 89% identity to beta-tubulin of the sporozoan (also a protoctist) Plasmodium falciparum. Fungal beta-tubulins are among the least identical to A. klebsiana beta-tubulin. Through Southern blot hybridization analysis, we determined that there is just one form of beta-tubulin gene in A. klebsiana. Transcription of the gene was studied during sporogenesis. Following induction of sporogenesis, the level of the mRNA increased markedly at 2 h and declined in the next 2 h when mitosis, cytokinesis, and spore development occurred. At the same time, beta-tubulin content increased about 6-fold in the cells. Sporulation in A. klebsiana is not inhibited by antimitotic drugs such as benomyl, colcemid, and colchicine. Benomyl resistance in Neurospora crassa and Aspergillus nidulans has been genetically and molecularly linked to single amino acid substitutions at positions 167 and 165, respectively. The change from phenylalanine to tyrosine conferring benomyl resistance to N. crassa is seen in A. klebsiana, but the valine substitution for alanine in A. nidulans is marked by cysteine replacement in A. klebsiana. The amino acid found at position 165 is not conserved in various beta-tubulins, but phenylalanine at position 167 is extremely conserved.
 ...
PMID:Cloning and analysis of beta-tubulin gene from a protoctist. 239 20

We have constructed a mammalian expression vector consisting of 3 kilobases of the human beta-actin gene 5' flanking sequence plus 5' untranslated region and intervening sequence 1 linked at the 3' splice site to a short DNA polylinker sequence containing unique Sal I, HindIII, and BamHI restriction endonuclease sites followed by a simian virus 40 (SV40) polyadenylylation signal. Two derivatives, containing the selection markers obtained from pSV2gpt or pSV2neo, were also generated. We find that the promoter activity of this vector is a great or greater than that of the SV40 early promoter in a variety of human and rodent cells. The vector was used to generate gamma-actin and beta-tubulin antisense transcripts in human fibroblast cell lines. The antisense transcripts accumulate to levels comparable with that of the highly abundant gamma-actin and beta-tubulin mRNAs.
 ...
PMID:A human beta-actin expression vector system directs high-level accumulation of antisense transcripts. 244 31

Aspergillus niger transformation frequencies of up to 1,176 transformants per micrograms DNA were achieved using the plasmid vector pSTA10 containing the A. niger nitrate reductase structural gene. Analysis of genomic endonuclease cleaved DNA from nitrate utilising transformants by DNA hybridisation, showed that most integration events are as a result of homologous recombination. The niaD transformation system was used successfully for the introduction of the unselected Escherichia coli fusion genes lacZ, encoding beta-galactosidase, and uidA, for beta-glucuronidase, as well as the Neurospora crassa tub-2 gene, for beta-tubulin. pSTA10 was also capable of transforming niaD mutants of other filamentous fungi such as A.nidulans, A. oryzae and Penicillium chrysogenum.
 ...
PMID:Improved transformation efficiency of Aspergillus niger using the homologous niaD gene for nitrate reductase. 279 Oct 35

The organization of the alpha- and beta-tubulin gene families in Physarum was investigated by Mendelian analysis. Restriction endonuclease-generated DNA fragments homologous to alpha- and beta-tubulin show length polymorphisms that can be used as markers for genetic mapping. Analysis of meiotic assortment among progeny of heterozygotes allowed alpha- and beta-tubulin sequence loci to be defined. There are four unlinked alpha-tubulin sequence loci (altA, altB, altC and altD) and at least three unlinked beta-tubulin sequence loci (betA, betB and betC). The alpha-tubulin loci are not linked to the beta-tubulin loci. --Segregation of tubulin sequence loci with respect to ben mutations that confer resistance to antitubulin benzimidazole drugs was used to investigate whether any members of the alpha- or beta-tubulin gene families are allelic to ben loci. The beta-tubulin sequence locus betB is allelic to the resistance locus benD, the betA locus is probably allelic to benA and the alpha-tubulin sequence locus altC may be allelic to benC. The molecular implications of benzimidazole resistance phenotypes when only one of the expressed beta-tubulin gene family members mutates to drug resistance are discussed in relation to tubulin function.
 ...
PMID:Genetics of the tubulin gene families of Physarum. 609 Feb 67

African trypanosomes are the causative agents of many medically and economically important diseases of man and domestic animals. The cell body of these blood-dwelling protozoa is enveloped with a dense layer of pellicular microtubules, which confer both motility and mechanical stability on these cells; microtubules are also important components of the flagellum. The major structural components of the microtubuli are two related proteins, alpha- and beta-tubulin. We have analyzed the genomic organization of alpha- and beta-tubulin genes in Trypanosoma brucei. In this organism, the majority of these genes are arranged in a single, tightly packed cluster of alternating alpha- and beta-tubulin genes with a basic repeat length together of 3.6 kilobase pairs. A genomic library of T. brucei was constructed by using the phage vector A 1059, and recombinant phages carrying tubulin genes were isolated by screening the library with heterologous chicken tubulin cDNA probes. The results of restriction endonuclease and hybridization analysis of DNA isolated from recombinant phages, and subcloned fragments thereof, were compatible with the restriction maps derived from digestion and Southern blot hybridization of genomic DNA.
 ...
PMID:Tubulin genes of Trypanosoma brucei: a tightly clustered family of alternating genes. 630 33

We have examined the similarities and differences in the organization of tubulin genes in New World Leishmania by restriction endonuclease digestion of genomic DNA and Southern blot analysis, using heterologous and homologous tubulin gene probes. As judged by the hybridization pattern and the restriction fragment length polymorphism (RFLP), there were large differences in both the restriction and hybridization patterns of the beta-tubulin sequences between stocks of the mexicana and braziliensis complexes. There were similarities in the hybridization patterns of different species of the mexicana complex. In contrast, a high heterogeneity was found between species of the braziliensis complex which includes intraspecific variation. The results suggest that this polymorphism may be associated with random mutations. The same analysis gave evidence of large differences in the beta-tubulin gene restriction pattern between New and Old World Leishmania. This variation in the beta-tubulin gene region was sufficient to distinguish between New and Old World Leishmania groups and between stocks of the mexicana and braziliensis complexes.
 ...
PMID:The RFLP analysis of the beta-tubulin gene region in New World Leishmania. 760 83

Control of Helminthosporium solani, the cause of silver scurf in potato tubers, has been impaired by selection of benzimidazole-resistant strains as a result of repeated use of the fungicide thiabendazole. Identification of thiabendazole-resistant strains of H. solani by conventional techniques takes several weeks. Primers designed from conserved regions of the fungal beta-tubulin gene were used to PCR amplify and sequence a portion of the gene. A point mutation was detected at codon 198 in thiabendazole-resistant isolates causing a change in the amino acid sequence from glutamic acid to alanine or glutamine. Species-specific PCR primers designed to amplify this region were used in conjunction with a restriction endonuclease to cause cleavage in sensitive isolates only and thus provide a rapid diagnostic test to differentiate field isolates.
 ...
PMID:A PCR-based method to characterise and identify benzimidazole resistance in Helminthosporium solani. 923 30

A system based on PCR and restriction endonuclease analysis was developed to distinguish the seven currently recognized Malassezia species. Seventy-eight strains, including authentic culture collection strains and routine clinical isolates, were investigated for variation in the ribosomal DNA repeat units. Two genomic regions, namely, the large subunit of the ribosomal gene and the internal transcribed spacer (ITS) region, were amplified by PCR, and products were digested with restriction endonucleases. The patterns generated were useful in identification of five out of seven Malassezia species. M. sympodialis was readily distinguishable in that its ITS region yielded a 700-bp amplified fragment, whereas the other six species yielded an 800-bp fragment. M. globosa and M. restricta were very similar in the regions studied and could be distinguished only by performing a hot start-touchdown PCR on primers for the beta-tubulin gene. Primers based on the conserved areas of the Candida cylindracea lipase gene, which were used in an attempt to amplify Malassezia lipases, yielded an amplification product after annealing at 55 degrees C only with M. pachydermatis. This specific amplification may facilitate the rapid identification of this organism.
 ...
PMID:Molecular differentiation of seven Malassezia species. 1079 Jan 15

Genomic libraries were constructed from three Drosophila species, namely Drosophila auraria, Drosophila serrata, and Drosophila kikkawai, belonging to the Drosophila montium subgroup of the Drosophila melanogaster species group. Clones containing beta-tubulin specific sequences were isolated, characterized by restriction endonuclease digestions and Southern hybridizations, and mapped by in situ hybridization on the polytene chromosomes of the species studied. The distribution of the beta-tubulin loci was found to be similar in D. montium species and D. melanogaster.
 ...
PMID:Isolation, characterization, and localization of beta-tubulin genomic clones of three Drosophila montium subgroup species. 1203 31

Monilinia laxa is a pathogen of brown rot of stone fruit and almond in California, causing blossom blights and fruit rots. In this study, low-level resistance to the benzimidazole fungicides benomyl and thiophanate-methyl was detected in field isolates of M laxa collected from stone fruits and almonds in California. Low-resistant (LR) isolates grew in potato dextrose agar (PDA) plates amended with benomyl and thiophanate-methyl at 1 and 5 microg ml(-1), respectively, but not in plates amended with benomyl at 5 microg ml(-1) or thiophanate-methyl at 50 microg ml(-1). The benzimidazole LR isolates were characterized by temperature sensitivity and the DNA sequence of the beta-tubulin gene. The LR isolates showed high-temperature sensitivity, being sensitive to 1 microg ml(-1) of benomyl at 28 degrees C but resistant at 8-24 degrees C. Analysis of the DNA sequence of the beta-tubulin gene showed that the LR isolates had a point mutation at the amino-acid position 240, causing substitution of leucine by phenylalanine. Based on the point mutation, a pair of allele-specific PCR primers was developed for rapid detection of LR isolates of M laxa. In addition, a pair of PCR primers specific to M laxa was developed on the basis of the differences in the DNA sequence of the intron 6 of beta-tubulin gene from M laxa, M fructicola and other fungal species. The primer pair amplified the expected 376-bp DNA fragment from all M laxa isolates tested, but not from 14 other fungal species isolated from stone fruit and almond crops. The restriction endonuclease BsmA I recognized the sequence GTCTCC in the PCR products from sensitive (S) isolates only, but not the GTTTCC sequence in the PCR products from LR isolates. The endonuclease digested the 376-bp PCR products from S isolates to produce two bands (111 and 265 bp) on agarose gels. Thus, both allele-specific PCR and the PCR-restriction fragment length polymorphism (PCR-RFLP) methods could be useful for rapidly detecting benzimidazole-resistant isolates of M laxa from stone fruit and almond crops in California.
 ...
PMID:Characterization and PCR-based detection of benzimidazole-resistant isolates of Monilinia laxa in California. 1581 17


1