tailieunhanh - The modeled structures of Deg5 and Deg8 proteases in Arabidopsis thaliana

Deg5 and Deg8 are chloroplastic proteases found in Arabidopsis thaliana. These proteases participate in the repair of photosystem II. However, little information exists on the structures of Deg5 and Deg8. | Turkish Journal of Biology Research Article Turk J Biol (2014) 38: 168-176 © TÜBİTAK doi: The modeled structures of Deg5 and Deg8 proteases in Arabidopsis thaliana Liangbing CHEN*, Qingzhi LI, Lili LI Department of Life Science, Zhoukou Normal University, Zhoukou, . China Received: Accepted: Published Online: Printed: Abstract: Deg5 and Deg8 are chloroplastic proteases found in Arabidopsis thaliana. These proteases participate in the repair of photosystem II. However, little information exists on the structures of Deg5 and Deg8. Here, the Deg5 and Deg8 structures were modeled using the SWISS-MODEL tool with Deg1 as the structural template. Deg5 was composed of only 1 domain, a protease domain. The catalytic triad of Deg5, which comprises His147, Asp188, and Ser266, was located in the cleft between 2 β-barrels. Deg8 was composed of a protease domain at the N-terminal and a PDZ domain at the C-terminal. The catalytic triad of Deg8, which comprises His171, Asp214, and Ser292, was also located in the cleft between 2 β-barrels. Key words: Deg protease, serine protease, domain, catalytic triad, photosystem II 1. Introduction The degradation of periplasmic proteins (Deg) proteases are ATP-independent serine proteases. Deg proteases contain one protease domain with histidine (His), aspartic acid (Asp), and serine (Ser) forming the catalytic triad; this domain is responsible for substrate hydrolysis and the subunit interaction between the homo-oligomeric complexes of Deg proteases (Schuhmann et al., 2012). In addition to the protease domain, most Deg proteases are composed of at least 1 PSD-95/SAP90, disc-large, and ZO-1 protein (PDZ) domain with 3 major biological functions: mediating subunit interaction among homo-oligomeric complexes (Kim et al., 2005; Krojer et al., 2008), recognizing the substrate, and activating the protease domain (Walsh et al., 2003). .