Understanding the selectivity of lysine negatively charged acyl modifications by OsCobB and its link with different plant stress condition

Abstract

Recent proteomic studies have found several different lysine modifications in plants related to various important metabolic pathways. Lysine deacylation is a key feature of sirtuins for the regulation of several cellular processes in mammals. This may be involved in the tolerance against different stress conditions in case of plants. In this study, we deliver a comprehensive structural and kinetic analysis describing the selection of lysine acidic acyl groups by OsCobB. The catalytic efficiency (kcat/Km) of OsCobB to erase glutaryl, succinyl, and malonyl groups from the designated lysine site is favored due to the presence of Tyr55 and Arg58 at the active site. The selectivity of the substrate is further based on the OsCobB active site residues as well as residues next to the modified lysine. These modifications can be further linked to the plants mechanism to cope with stress due to dehydration, cold temperature and different metal toxicities.