@unpublished{14644,
  abstract     = {Transcription by RNA polymerase II (Pol II) can be repressed by noncoding RNA, including the human RNA Alu. However, the mechanism by which endogenous RNAs repress transcription remains unclear. Here we present cryo-electron microscopy structures of Pol II bound to Alu RNA, which reveal that Alu RNA mimics how DNA and RNA bind to Pol II during transcription elongation. Further, we show how domains of the general transcription factor TFIIF affect complex dynamics and control repressive activity. Together, we reveal how a non-coding RNA can regulate mammalian gene expression.},
  author       = {Tluckova, Katarina and Testa Salmazo, Anita P and Bernecky, Carrie A},
  publisher    = {Institute of Science and Technology Austria},
  title        = {{Mechanism of mammalian transcriptional repression by noncoding RNA}},
  doi          = {10.15479/AT:ISTA:14644},
  year         = {2023},
}

@article{15061,
  abstract     = {The actin cytoskeleton, a dynamic network of actin filaments and associated F-actin–binding proteins, is fundamentally important in eukaryotes. α-Actinins are major F-actin bundlers that are inhibited by Ca2+ in nonmuscle cells. Here we report the mechanism of Ca2+-mediated regulation of Entamoeba histolytica α-actinin-2 (EhActn2) with features expected for the common ancestor of Entamoeba and higher eukaryotic α-actinins. Crystal structures of Ca2+-free and Ca2+-bound EhActn2 reveal a calmodulin-like domain (CaMD) uniquely inserted within the rod domain. Integrative studies reveal an exceptionally high affinity of the EhActn2 CaMD for Ca2+, binding of which can only be regulated in the presence of physiological concentrations of Mg2+. Ca2+ binding triggers an increase in protein multidomain rigidity, reducing conformational flexibility of F-actin–binding domains via interdomain cross-talk and consequently inhibiting F-actin bundling. In vivo studies uncover that EhActn2 plays an important role in phagocytic cup formation and might constitute a new drug target for amoebic dysentery.},
  author       = {Pinotsis, Nikos and Zielinska, Karolina and Babuta, Mrigya and Arolas, Joan L. and Kostan, Julius and Khan, Muhammad Bashir and Schreiner, Claudia and Testa Salmazo, Anita P and Ciccarelli, Luciano and Puchinger, Martin and Gkougkoulia, Eirini A. and Ribeiro, Euripedes de Almeida and Marlovits, Thomas C. and Bhattacharya, Alok and Djinovic-Carugo, Kristina},
  issn         = {1091-6490},
  journal      = {Proceedings of the National Academy of Sciences},
  number       = {36},
  pages        = {22101--22112},
  publisher    = {Proceedings of the National Academy of Sciences},
  title        = {{Calcium modulates the domain flexibility and function of an α-actinin similar to the ancestral α-actinin}},
  doi          = {10.1073/pnas.1917269117},
  volume       = {117},
  year         = {2020},
}