Naslov
A new look at SSB proteins

Autori
Paradžik, Tina ; Ivić, Nives ; Filić, Želimira ; Herron, Paul ; Manjasetty, Babu A. ; Luić, Marija ; Vujaklija, Dušica

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, ostalo

Izvornik
Actinobacteria within soils, Capacities for mutualism symbiosis pathogenesis / Schrempf, Hilde ; Ortiz de Orue Lucana, Dario - Osnabrück : Sveučilište Osnabrueck, 2012, 49-49

Skup
Actinobacteria within soils

Mjesto i datum
Münster, Njemačka, 25.10.2012. - 28.10.2012

Vrsta sudjelovanja
Pozvano predavanje

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
Streptomyces ; paralogous ssb genes ; chromosomal segregation ; crystal structures

Sažetak
Streptomycetes are saprophytic soil bacteria that exhibit complex life cycle resembling those of eukaryotes, such as Fungi. The linear chromosome of Streptomyces coelicolor contains two paralogous genes encoding single- stranded DNA binding proteins, ssbA and ssbB. The functions of these SSBs (SSB-A and SSB-B) have not been studied so far. By disrupting these genes we have shown that ssbA gene is indispensable for cell viability, while ssbB participate in genome segregation during sporulation. Mutant phenotype has been restored by the introduction of single copy of ssbB gene. We also demonstrated differential expression of two ssb genes in S. coelicolor. During bacterial growth, gene ssbA is constantly expressed at higher level ; its expression is decreasing towards late stationary phase, while the expression of ssbB is at all-time low. In minimal medium the ssbB gene is significantly up regulated. Promoters for both genes are determined. Surprisingly, promoter of ssbB gene possesses unusual features and is active in taxonomically distant bacteria Escherichia coli. The solved crystal structure of SSB-S protein reveals a common conserved OB-fold, lack of clamp like structure and previously unpublished S-S bridges. Further, comparative sequence analysis of SSB proteins from Actinobacteria was also performed revealing frequent duplication of ssb gene. Strong retention of ssb genes could be result of adoption of important cellular function.

Izvorni jezik
Engleski

Znanstvena područja
Kemija, Biologija

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