<> "The repository administrator has not yet configured an RDF license."^^ . <> . . "Analysis of retroviral assembly and maturation using cryo-electron tomography"^^ . "Retroviruses are a family of membrane-enveloped RNA viruses that can retrotranscribe\r\nand integrate their genome in the host cell chromatin. During the active\r\nproduction of virions the structural polyprotein Gag assembles together with the\r\ngenomic RNA to form immature particles, which bud out from the host cell. After\r\nbudding the Gag protein undergoes proteolytic maturation and is cleaved into MA,\r\nCA, NC, p6 and two spacer peptides, SP1 and SP2. This leads to dramatic changes in\r\nthe core morphology and the gain of infectivity. The immature retro-virions are\r\nknown to have Gag organized into a round, incomplete hexameric lattice with a\r\nspacing of ~7.5nm. The core of mature virions is organized into a mixture of\r\nhexamers and pentamers which are organized along a lattice with a spacing of\r\n~9.6nm. The shape of the core in the mature virions is genus-dependent, but can be\r\ncylindrical, conical or round.\r\nDuring my PhD I have studied the immature Gag assembly across four retroviral\r\ngenera in order to understand the structural requirements for the assembly of the\r\nimmature retroviral lattice, and to shed more light on the principles of HIV-1\r\nmaturation.\r\nThe major conclusions of my studies are the following: The CA region of Gag is the\r\nmost structurally conserved across genera. The presence of a domain upstream of CA\r\nis not critical for the assembly although it stabilizes the lattice. In order to maintain an\r\nimmature lattice is important to have a Gag multimerization domain downstream of\r\nCA. The region between CA and NC, which is highly variable, is not critical for the\r\nassembly but it can stabilise the lattice and therefore affect the structural changes that\r\noccur during the maturation.\r\nThe maturation in retroviruses is an extremely fast process. In order to investigate the\r\nstructural changes occurring during the maturation in HIV-1 I analysed the products\r\nof partial Gag maturation, which were obtained through selective mutations of the\r\ncleavage sites in Gag. This confirmed that the order in which Gag cleavages occur is\r\nimportant for a correct processing. The immature Gag lattice is destabilized only if\r\nboth sides of the CA-SP1 region are cleaved. Furthermore, it showed that the\r\ncondensation of the RNP has an effect on the core morphology in the mature virion."^^ . "2013" . . . . . . . "Alex"^^ . "de Marco"^^ . "Alex de Marco"^^ . . . . . . "Analysis of retroviral assembly and maturation using cryo-electron tomography (PDF)"^^ . . . "thesis_demarco_print.pdf"^^ . . . "Analysis of retroviral assembly and maturation using cryo-electron tomography (Other)"^^ . . . . . . "indexcodes.txt"^^ . . . "Analysis of retroviral assembly and maturation using cryo-electron tomography (Other)"^^ . . . . . . "lightbox.jpg"^^ . . . "Analysis of retroviral assembly and maturation using cryo-electron tomography (Other)"^^ . . . . . . "preview.jpg"^^ . . . "Analysis of retroviral assembly and maturation using cryo-electron tomography (Other)"^^ . . . . . . "medium.jpg"^^ . . . "Analysis of retroviral assembly and maturation using cryo-electron tomography (Other)"^^ . . . . . . "small.jpg"^^ . . "HTML Summary of #15685 \n\nAnalysis of retroviral assembly and maturation using cryo-electron tomography\n\n" . "text/html" . . . "570 Biowissenschaften, Biologie"@de . "570 Life sciences"@en . .