22 research outputs found
The wonders of flap endonucleases: structure, function, mechanism and regulation.
Processing of Okazaki fragments to complete lagging strand DNA synthesis requires coordination among several proteins. RNA primers and DNA synthesised by DNA polymerase α are displaced by DNA polymerase δ to create bifurcated nucleic acid structures known as 5'-flaps. These 5'-flaps are removed by Flap Endonuclease 1 (FEN), a structure-specific nuclease whose divalent metal ion-dependent phosphodiesterase activity cleaves 5'-flaps with exquisite specificity. FENs are paradigms for the 5' nuclease superfamily, whose members perform a wide variety of roles in nucleic acid metabolism using a similar nuclease core domain that displays common biochemical properties and structural features. A detailed review of FEN structure is undertaken to show how DNA substrate recognition occurs and how FEN achieves cleavage at a single phosphate diester. A proposed double nucleotide unpairing trap (DoNUT) is discussed with regards to FEN and has relevance to the wider 5' nuclease superfamily. The homotrimeric proliferating cell nuclear antigen protein (PCNA) coordinates the actions of DNA polymerase, FEN and DNA ligase by facilitating the hand-off intermediates between each protein during Okazaki fragment maturation to maximise through-put and minimise consequences of intermediates being released into the wider cellular environment. FEN has numerous partner proteins that modulate and control its action during DNA replication and is also controlled by several post-translational modification events, all acting in concert to maintain precise and appropriate cleavage of Okazaki fragment intermediates during DNA replication
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The May 1 Marchers in Los Angeles: Overcoming Conflicting Frames, Bilingual Women Connectors, English-Language Radio, and Newly Politicized Spanish Speakers
In this article, we study protest participants in the May 2006 immigration rights marches in Los Angeles. Analysis of original survey data of 876 march participants yields five main results. First, despite substantial dispute among organizers on how to frame the marches, we find protest participants were similar across march locations organized by different coalitions. Second, we find Spanish-English bilingual participants seemed to benefit from being in two media environments, as they reported more information sources about the protest events than monolingual participants. Third, women reported hearing about the protest events from more information sources, and Spanish-English bilingual women reported hearing from more information sources than any other group, suggesting they acted as social connectors behind the massive participation. Fourth, we confirm the importance of Spanish-language radio as an information source, but our data also point to the significance of television and English-language radio. Finally, analyzing data of first-time protesters, we estimate the immigrant rights marches newly politicized 125,000 people in Los Angeles who spoke Spanish and not English
Ethics in Political Science Research
Ethical dilemmas are much more common in political science than it is commonly envisaged. In this chapter we use the tripartite division between politics, polity, and policies and discuss the specific ethical concerns of these three core areas of research in political science. Additionally, we discuss some of the current and future challenges of research ethics in the field addressing ethics issues related to the use experiments, digital media, and the adoption of research designs that rest on action research. Overall, ethics considerations have become – and will become – increasingly important also in political science