Isolation and nucleotide sequence of an autonomously replicating sequence (ARS) element functional in Candida albicans and Saccharomyces cerevisiae

Abstract

An 8.6-kb fragment was isolated from an EcoRI digest of Candida albicans ATCC 10261 genomic DNA which conferred the property of autonomous replication in Saccharomyces cervisiae on the otherwise non-replicative plasmid pMK155 (5.6 kb). The DNA responsible for the replicative function was subcloned as a 1.2-kb fragment onto a non-replicative plasmid (pRC3915) containing the C. albicans URA3 and LEU2 genes to form plasmid pRC3920. This plasmid was capable of autonomous replication in both S. cerevisiae and C. albicans and transformed S. cerevisiae AH22 (leu2-) to Leu+ at a frequency of 2.15 x 10(3) transformants per microgram DNA, and transformed C. albicans SGY-243 (delta ura3) to Ura+ at a frequency of 1.91 x 10(3) transformants per microgram DNA. Sequence analysis of the cloned DNA revealed the presence of two identical regions of eleven base pairs (5'TTTTATGTTTT3') which agreed with the consensus of autonomously replicating sequence (ARS) cores functional in S. cerevisiae. In addition there were two 10/11 and numerous 9/11 matches to the core consensus. The two 11/11 matches to the consensus, CaARS1 and CaARS2, were located on opposite strands in a non-coding AT-rich region and were separated by 107 bp. Also present on the C. albicans DNA, 538 bp from the ARS cores, was a gene for 5S rRNA which showed sequence homology with several other yeast 5S rRNA genes.(ABSTRACT TRUNCATED AT 250 WORDS)