A novel acetyltransferase (Mpr1) found in Saccharomyces cerevisiae (strain Sigma1278b) has been shown to specifically detoxify a proline analog, l-azetidine-2-carboxylic acid (A2C) in yeast cells [M. Shichiri et al. (2001) J Biol Chem 276: 41998-42002]. We investigated whether the yeast MPR1 gene