The 30th International Conference on Arabidopsis Research (ICAR 2019)

683 / 2019-05-01 03:23:35

Aminoacids motifs responsible for activity properties and metal ions preferences of S1/P1-like nucleases

nucleases,pcd,enzymology,catalytic properties

Plenary track > Cell Biology

Programmed cell death (PCD) is one of the most important cell process, plays crucial role in morphogenesis, defense responses to pathogens and other stress conditions. Although in animals and plants, degradation of cellular DNA and RNA is a inherent step of PCD, role and mechanism of this process it’s different. Previous studies have demonstrated that S1/P1 nucleases are mainly responsible of nucleic acids degradation in plants. As a result of their high homology, to well described fungus nucleases S1 and P1 with catalytic activity in low pH and in presence of zinc-ions, it was assumed that the same conditions occurs during hydrolysis of the plant’s DNA and RNA. In spite of this, our research exhibits that plant S1/P1 nucleases have a high diversity of the catalytic requirements. Some of them demonstrate activity in neutral pH and in presence of calcium or manganese ions, while low pH and zinc ions inhibit their activity. These information could lead to described a exact step of PCD and when degradation of nucleic acids occurs. To better understand structures features responsible for enzymatic properties of plants S1 nucleases, we performed a directed mutagenesis of regions close to activity center of ENDONUCLEASE 4 (AT4G21585) and examined influence of this mutations synergistically or independently on activity properties of enzyme.

Supported by Wydzialu Biologii UAM - POWER.03.02.00-00-I006/17; Grant NCN no. 2014/15/NZ3/00863