Identification of two CyP-40-like cyclophilins in Saccharomyces cerevisiae, one of which is required for normal growth.

We report the analysis of two Saccharomyces cerevisiae cyclophilins, Cpr6 and Cpr7, identified by their ability to interact in vivo with the transcriptional regulator Rpd3. Both cyclophilins have an extended carboxy-terminal region containing a three-unit tetratricopeptide repeat (TPR) motif and share significant amino acid identity with the mammalian cyclophilin CyP-40. Neither CPR6 nor CPR7 is essential but deletion of CPR7 results in a significant impairment of the rate of cell division. This is the first demonstration that a member of the cyclophilin family is required for normal cell growth.