The binding interface was probed with point mutations, none of which had a noticeable effect on dimer formation; however deletion

of the C-terminal tail region prevented dimer formation in vivo. The structure provides a template for future biochemical studies and modelling of ICP27 homologs from other herpesviruses.”
“The turtle body plan, with its solid shell, deviates radically from those of other tetrapods. The dorsal part of the turtle shell, or the carapace, consists mainly of costal and neural bony plates, which are continuous with the underlying thoracic ribs and vertebrae, respectively. Because of their superficial position, the evolutionary origins of these costo-neural elements have long remained elusive. Here we show, through comparative morphological and embryological analyses, that the major part of the carapace is derived Selleckchem NSC 23766 purely from endoskeletal ribs. We examine turtle embryos and find that the costal and neural plates develop not within the dermis, but within deeper connective tissue where the rib and intercostal muscle anlagen

develop. We also examine the fossils of an outgroup of turtles to confirm that Autophagy inhibitor manufacturer the structure equivalent to the turtle carapace developed independently of the true osteoderm. Our results highlight the hitherto unravelled evolutionary course of the turtle shell.”
“DNA replication in eukaryotes is a highly conserved process marked by the licensing of multiple origins, with pre-replication complex assembly in G1 phase, followed by the onset of replication at these origins in S phase. The two strands replicate by different mechanisms, this website and DNA synthesis is brought about by the activity of the replicative DNA polymerases Pol delta and Pol epsilon. Proliferating cell nuclear antigen (PCNA) augments the processivity of these polymerases by serving as a DNA sliding clamp protein. This study reports the cloning

of PCNA from the protozoan Leishmania donovani, which is the causative agent of the systemic disease visceral leishmaniasis. PCNA was demonstrated to be robustly expressed in actively proliferating L. donovani promastigotes. We found that the protein was present primarily in the nucleus throughout the cell cycle, and it was found in both proliferating procyclic and metacyclic promastigotes. However, levels of expression of PCNA varied through cell cycle progression, with maximum expression evident in G1 and S phases. The subnuclear pattern of expression of PCNA differed in different stages of the cell cycle; it formed distinct subnuclear foci in S phase, while it was distributed in a more diffuse pattern in G2/M phase and post-mitotic phase cells.