Protein Engineering, Vol. 13, No. 2, 73-76,
February 2000
© 2000 Oxford University Press
Communication |
Lethal effect of the expression of a killer gene SMK1 in Saccharomyces cerevisiae
National Food Research Institute, 2-1-2 Kannondai, Tsukuba, Ibaraki305-8642, 2 Japan Women's University, Faculty of Home Economics,2-8-1 Mejirodai, Bunkyo-ku, Tokyo 112-8681, 3 Protein Engineering Research Institute, 6-2-3, Furuedai, Suita, Osaka 565-0874 and 5 Water Research Institute, 2-1-6, Sengen, Tsukuba, Ibaraki 305-0047, Japan
Expression of the SMK1 gene which encodes the yeast killer toxin SMKT is lethal in Saccharomyces cerevisiae. Effects of deletion and site-directed mutagenesis of SMK1 on the lethality and the secretion of the gene products were examined. Deletion of the interstitial 
peptide or the C-terminal loop from Ala208 to the C-terminal Asp222 had no effect on the lethality. Those SMK1 products that lacked either the peptide or the C-terminal loop were expressed in the cells but were not secreted into the culture medium, suggesting that these peptides may have a role in secretion or in protein stability. On the other hand, deletion of the signal sequence resulted in complete loss of the lethal activity. Entering the secretory pathway may be critical for the lethality. Further, deletion of the region from the C-terminus to Leu207 resulted in loss of the lethal activity. Leu207 is located at the C-terminus of the central strand of the ß-sheet structure of SMKT and its side chain is thrust into a hydrophobic environment between the ß-sheet and the 
-helices. The result obtained upon substitutions of Ala, Ser or Glu for Leu207 suggested that the side chain of Leu207 stabilizes the hydrophobic environment that contributes to the overall structure of the SMK1 product.
CiteULike 
Connotea 
Del.icio.us What's this?
This article has been cited by other articles:
|
|
 |
|
  A. Fleissner and N. L. Glass SO, a Protein Involved in Hyphal Fusion in Neurospora crassa, Localizes to Septal Plugs Eukaryot. Cell, January 1, 2007; 6(1): 84 - 94. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 I. Kaneko, K. Dementhon, Q. Xiang, and N. L. Glass Nonallelic Interactions Between het-c and a Polymorphic Locus, pin-c, Are Essential for Nonself Recognition and Programmed Cell Death in Neurospora crassa. Genetics, March 1, 2006; 172(3): 1545 - 1555. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 C. Suzuki, T. Kashiwagi, and K. Hirayama Alternative CUG codon usage (Ser for Leu) in Pichia farinosa and the effect of a mutated killer gene in Saccharomyces cerevisiae Protein Eng. Des. Sel., March 1, 2002; 15(3): 251 - 255. [Abstract] [Full Text] [PDF]
|
|