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SUMMARY:Structure and function of macromolecular machines involved in infe
 ction of prokaryotic and eukaryotic cells
DTSTART:20090625T121500
DTSTAMP:20260408T173932Z
UID:7c7591c0fb630f40b2db67e89fde006b627be9a55bfe4e5f581fa398
CATEGORIES:Conferences - Seminars
DESCRIPTION:Petr Leiman\nA majority of bacterial viruses (bacteriophages) 
 use a multicomponent macromolecular machine\, called a tail\, to infect th
 eir host cells. The tail and fibers\, which emanate from the tail\, coordi
 nate the infection process and allow the phage to penetrate through the mu
 ltilayered host cell envelope\, which consists of the external polysacchar
 ide\, two lipid membranes and the intervening peptidoglycan layer. Current
 ly\, there are 3 types of tails known and they differ in their complexity 
 and the mode of action. For example\, at least 22 genes participate in the
  assembly of the bacteriophage T4 tail\, and the combined size of these ge
 nes is greater than the entire genome of adenovirus\, which is considered 
 to be a complex eukaryotic virus. Notably\, most probably due to the funct
 ion of the tail\, infectivity of phages is much greater than that of eukar
 yotic viruses and approaches 100% in laboratory conditions.\nEvolutionary 
 ancestry of tails represents an unsolved puzzle of microbiology. However\,
  several recent findings suggest that a macromolecular complex resembling 
 a tail is present in bacteria. This structure shows properties of a secret
 ion system\, which has been categorized at the Type VI Secretion System (T
 6SS). The T6SS gene cluster is present in many pathogenic bacteria and has
  been shown to be a virulence factor for several bacterial pathogens. Rema
 rkably\, using this tail-like structure\, bacteria are able to translocate
  large proteins directly into the cytoplasm of eukaryotic cells.\nThe foll
 owing topics will be discussed: 1) the structure and function of key prote
 ins from phage tails\; 2) the type VI secretion system\; 3) possible appli
 cation of phage tails as tunable antimicrobials.
LOCATION:SV 1717A
STATUS:CONFIRMED
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