Molekulare Analyse des Kernfreisetzungskomplexes des Pseudorabies Virus Herpesviruses use a vesicle mediated transport for translocation of nucleocapsids from the nucleus to the cytoplasm for final virus maturation. Two conserved herpesviral proteins designated as pUL34 and pUL31 form the nuclear egress complex which is required for efficient nuclear egress. The crystal structures of NECs from different herpesviruses showed a tight interaction of the N terminal domain of pUL31 forming a hook like extension clamping the core of pUL34. Furthermore the most conserved residues of pUL31 belong to a zinc finger motif (ZNF). To clarify the functional importance of the ZNF motif in PrV pUL31 which consists of three cysteines (C73 C89 and C92) contributed by the CR1 and a histidine (H188) from CR3 cysteines were individually substituted by serine residues and the histidine H188 was replaced by an alanine. Functional analyses of the mutant proteins performed in vitro with artificial membranes and in situ in eukaryotic cells showed that the ZNF motif is an essential prerequisite for NEC formation and the membrane remodeling activity. The N Terminus of the pUL31 homologs is variable and highly flexible and was therefore omitted in the constructs used for crystallization. Like several other pUL31 homologs PrV pUL31 contains a nuclear localization signal (NLS) in the N terminus for efficient nuclear targeting. In addition to being a transport signal other functions have been suggested for this part as preventing premature complex formation in the ... Herpesviren Herpesvirus suis Kernhülle Fragmentierung Vesikel Nuclear Egress Nuclear Egress Complex primär umhüllte Virionen