Naslov
Tyrosine phosphorylation of bacterial SSBs from taxonomically distant bacterial species

Autori
Mijaković, Ivan ; Petranović, Mirjana ; Maček, Boris ; Čepo, Tina ; Mann, Matthias ; Davies, Julian ; Jensen, Peter, R. ; Vujaklija, Dušica

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

Izvornik
4th Congress of the Slovenian Microbiological Society with International Participation „Microbiology for today“ / Barlič-Maganja, Darja ; Raspor, Peter - Ljubljana : Slovenian Microbiological Society, 2008, 54-54

ISBN
978-961-90346-4-4

Skup
4th Congress of the Slovenian Microbiological Society with International Participation „Microbiology for today“

Mjesto i datum
Portorož, Slovenija, 19.11.2008. - 22.11.2008

Vrsta sudjelovanja
Pozvano predavanje

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
Tyrosine phosphorylation ; single-stranded DNA binding proteins ; SSB

Sažetak
Single stranded DNA binding proteins (SSBs) are essential proteins required in various stages of DNA metabolism. SSBs bind DNA in a sequence independent manner and maintain genome integrity during DNA replication, recombination or repair. The main role of SSB protein in the cell is to stabilize single-stranded DNA (ssDNA). It is also known that SSBs interact and modulate the activities of many enzymes such as DNA polymerase, RNA polymerase or DNA helicase. Bacterial SSBs are homo-tetramers, while eukaryotic are hetero-trimers. Although they differ considerably in the structure, these enzymes accomplish similar functions. Interestingly, eukaryotic SSBs are regulated by phosphorylation on several serine and threonine residues, while our recent discoveries pointed out that bacterial SSBs are phosphorylated on tyrosine residue(s). The first evidence has been obtained by immunoaffinity chromatography. We have purified tyrosine phosphorylated SSB from Streptomyces griseus. Since genes encoding protein-tyrosine kinases have not been recognized in streptomycetes and SSBs from Streptomyces coelicolor and Bacillus subtilis share 40% identity, we used B. subtilis protein-tyrosine kinase YwqD to examine phosphorylation of the two cognate SSBs (SSB and YwpH) in vitro. Focusing on this model system we found that phosphorylation of SSB is affected antagonistically by B. subtilis tyrosine kinase (YwqD) and phosphatase (YwqE). We showed next that phosphorylation of B. subtilis SSB significantly increased binding to single-stranded DNA in vitro. We also found decrease in SSB phosphorylation under DNA-damaging conditions in the cells. A significantly lower extent of phosphorylation suggested one biological aspect of this modification in the regulation

Izvorni jezik
Engleski

Znanstvena područja
Biologija

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