Figure 2From: MPN+, a putative catalytic motif found in a subset of MPN domain proteins from eukaryotes and prokaryotes, is critical for Rpn11 functionGrowth of rpn11 Mutants under Different Growth Conditions. WT and mutant strains were streaked on YPD at 25, 30 and 37°C. Cells were also plated on complete minimal media containing 1 μg/ml of the amino acid analog canavinine instead of arginine. Plates were photographed after 3–5 days. Three single amino acid substitutions in the MPN+ motif of Rpn11 were studied: his111ala, Ser119ala, and asp122ala. For comparison, a substitution of a highly conserved cysteine residue (cys116ala) that is not part of the MPN+ motif (see Fig. 1) was included as well. At 25°C, all MPN+ mutations are viable but slow growing. Hiss111 is extremely temperature sensitive, showing no appreciable growth even when shifted to 30°C, or in the presence of even 1 μg/ml of the amino acid analog canavinine. Asp122 and Ser119 substitutions show lethality under elevated temperature (37°C) or exposure to canavanine. In comparison, Cys116 substitutions show no growth defects under these conditions.Back to article page