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Zhang,Yu; Li,Zhen-Hua; Zheng,Wei; Tang,Zhen-Xing; Zhang,Zhi-Liang; Shi,Lu-E. |
Background: To identify the critical amino acid residues that contribute to the high enzyme activity and good thermostability of Yersinia enterocolitica subsp. palearctica (Y. NSN), 15 mutants of Y. NSN were obtained by site-directed mutagenesis in this study. And their enzyme activity and thermostability were assayed. Effect of several factors on the enzyme activity and thermostability of Y. NSN, was also investigated. Results: The results showed that the I203F and D264E mutants retained approximately 75% and 70% enzyme activity, respectively, compared to the wild-type enzyme. In addition to the I203F and D264E mutants, the mutant E202A had an obvious influence on the thermostability of Y. NSN. According to the analysis of enzyme activity and... |
Tipo: Journal article |
Palavras-chave: Factors affecting enzyme activity; Nuclease; Mutation; Mutagenesis; Nucleases without sequence specificity. |
Ano: 2016 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582016000600005 |
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Henneke, Ghislaine. |
Using model DNA substrates and purified recombinant proteins from Pyrococcus abyssi. I have reconstituted the enzymatic reactions involved in RNA primer elimination in vitro. In my dual-labelled system, polymerase D performed efficient strand displacement DNA synthesis, generating 5'-RNA flaps which were subsequently released by Fen1, before ligation by Lig1. In this pathway, the initial cleavage event by RNase HII facilitated RNA primer removal of Okazaki fragments. In addition, I have shown that polymerase B was able to displace downstream DNA strands with a single ribonucleotide at the 5'-end, a product resulting from a single cut in the RNA initiator by RNase HII. After RNA elimination, the combined activities of strand displacement DNA synthesis by... |
Tipo: Text |
Palavras-chave: Archaea; DNA ligase; DNA polymerase; Nuclease; Okazaki fragment. |
Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00107/21841/20923.pdf |
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FRANCO,OCTÁVIO LUIZ; GONDIM,LORRANCE ABREU; BEZERRA,KÁTIA REGINA; GUERRA,MARIA ELANE DE CARVALHO; LIMA,CARMEM ROGÉLIA FARIAS MACHADO; ENÉAS-FILHO,JOAQUIM; PRISCO,JOSÉ TARQUÍNIO; GOMES-FILHO,ENÉAS. |
Partial purification and characterization of ribonucleases (RNase; EC 3.1.27.1) present in roots, stem and leaves of 5 day-old Pitiúba cowpea [Vigna unguiculata (L.) Walp.] seedlings are described. Crude extracts from the different tissues were precipitated with ammonium sulfate followed by ionic exchange chromatography (CM-Cellulose) resulting in purification factors of 48-fold for roots, 21 for stem and 42 for leaves. No deoxyribonuclease activity was practically observed. The molecular masses of the RNases did not significantly differ, averaging 16.3 kDa. Leaf RNase was stable up to 50ºC while the others were inactivated at this temperature. The maximal inactivation for both stem and roots RNases was reached at 70ºC while for leaf it occurred at 80ºC.... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Enzyme effectors; Molecular mass; Nuclease; Optimum pH; Seedlings; Thermostability; Vigna unguiculata. |
Ano: 2001 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-31312001000300010 |
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