Salt‐Dependent Protein Splicing: In Vitro Enzymology and In vivo Physiological Relevance

Abstract

Protein splicing is a post‐translational process in which two separate polypeptides are produced from a single gene. Splicing involves the excision of an intervening protein sequence, called the intein, and ligation of the flanking exteins. Inteins have been found in halophilic archaea, including Halobacterium salinarum (Hsa), and previous work has demonstrated that in vitro splicing of the Hsa DNA Polymerase II (Polll) intein only occurs under reducing conditions with high salt concentrations. We compared the in vitro activity of the Hsa Polll intein to that of the only other Hsa intein, which interrupts a Cell Division Control protein (Cdc21a). The Hsa Cdc21a intein does not splice in E. coli, but can be induced to splice at similar conditions to the Hsa Polll intein in vitro. Additionally, we used a Cys1Ala mutation to study the extent of the third step of splicing. We are creating intein‐less strains of H. salinarum, and will use these to study the fitness cost of maintaining inteins under varying growth conditions.Support or Funding InformationThis work was supported by NASA (grant NNX15AM09G to RTP), the National Science Foundation (grants MCB1244089 and MCB1517138 to KVM) and the Dreyfus Foundation (KVM).This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.