We have investigated the sequence specificity of DNA damage induced by mitomycin C reduced with NaBH4, by using 3'- or 5'-end labeled DNA fragments of defined sequence. Mitomycin C reduced with NaBH4 induced heat-labile sites in DNA preferentially at specific sequences. The most preferred trinucleotide sequence for induction of heat-labile sites was GGT, followed by GGG, AGT, GAG, GGC and AGG. Active oxygens such as hydroxyl radical and singlet oxygen, and metal ions were involved in the induction of heat-labile sites. DNA was broken at the 3' side of deoxyguanosines and some of deoxyadenosines by heat-treatment. The produced oligonucleotides contained phosphoryl groups at the 5' termini. The 3' termini seemed not to have simple structures.
We have fused full length and the carboxyl-half of human MDR1 cDNA with the E. coli lacZ gene via a collagen linker and allowed their expression in yeast Saccharomyces cerevisiae. Using antibodies against beta-galactosidase we partially purified the fusion proteins by immunoprecipitation and show here that the full length fusion protein has ATPase activity. By contrast, the fusion protein containing the carboxyl-half of P-glycoprotein did not show ATPase activity, indicating that both domains of P-glycoprotein are necessary. By treatment of the immunoprecipitated fusion protein with collagenase, P-glycoprotein was released from the beta-galactosidase moiety. The results shown here open the possibility for a large scale purification of P-glycoprotein using this site specifically cleavable fusion protein.
Autoxidizable synthetic polysaccharides prepared by polycondensation of reducing aldose or ketose in dimethyl sulfoxide containing pohsphorus pentaoxide [Polymer, 13, 190 (1972)] inactivated phage φX174. Another autoxidizable polysaccharides obtained by oxidation of natural glucans with the same oxidant also inactivated φX174. The φX174 inactivation was due to strand scission of viral DNA in the virion. The inactivation reaction was stimulated by Cu2+ and inhibited by EDTA, superoxide dismutase, catalase and several radical scavengers.These results suggest that oxygen radicals produced during autoxidation of polysaccharides are responsible for φX174 inactivation.
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Journal Article Inactivation of Bacteriophage ϕX174 by d-Fructose 6-Phosphate Get access Junji Morita, Junji Morita Laboratory of Biochemistry, Department of Agricultural Chemistry, Kyoto University, Kyoto 606, Japan Search for other works by this author on: Oxford Academic Google Scholar Naoki Kashimura, Naoki Kashimura Laboratory of Biochemistry, Department of Agricultural Chemistry, Kyoto University, Kyoto 606, Japan Present address: Department of Agricultural Chemistry, Mie University, Tsu, Mie 514, Japan Search for other works by this author on: Oxford Academic Google Scholar Tohru Komano Tohru Komano Laboratory of Biochemistry, Department of Agricultural Chemistry, Kyoto University, Kyoto 606, Japan Search for other works by this author on: Oxford Academic Google Scholar Agricultural and Biological Chemistry, Volume 44, Issue 4, 1 April 1980, Pages 883–890, https://doi.org/10.1080/00021369.1980.10864034 Published: 01 April 1980 Article history Received: 12 November 1979 Published: 01 April 1980
We have cloned at least 12 different Escherichia coli genes which enable strain MK2001 to use maltose. The genes were designated sfs1 through sfs12 (sugar fermentation stimulation). Previously, one (sfs7) of them was mapped at 65 min on the E. coli chromosome and identified as nlp, which has high homology to repressor protein (Ner) of Mu phage, which contains a putative DNA binding region (Y.-L. Choi, T. Nishida, M. Kawamukai, R. Utsumi, H. Sakai, and T. Komano, J. Bacteriol. 171:5222-5225, 1989). In this study, another gene (sfs1) located at 3.5 min was newly found and analyzed. The nucleotide sequence of sfs1 encoded a protein of 234 amino acids (molecular mass, 26,227 Da) which also has a putative DNA binding domain. Overexpression of the sfs1 gene in MK2001 resulted in a 10-fold increase of amylomaltase, which was still dependent on MalT. These results suggest that Sfs1 could be a new regulatory factor involved in maltose metabolism.
