Identification and analysis of the origin recognition complex in the human fungal pathogen .

DNA replication in eukaryotes is initiated by the orchestrated assembly and association of initiator proteins (heterohexameric Origin Recognition Complex, ORC) on the replication origins. These functionally conserved proteins play significant roles in diverse cellular processes besides their central role in ignition of DNA replication at origins. , a major human fungal pathogen, is a diploid budding yeast that belongs to Ascomycota. However, is significantly diverged from a well-studied model organism , another ascomycete. The components of the DNA replication machinery in remain largely uncharacterized. Identification of factors required for DNA replication is essential for understanding the evolution of the DNA replication machinery. We identified the putative ORC homologs in and determined their relatedness with those of other eukaryotes including several yeast species. Our extensive studies demonstrate that the domain architecture of CaORC proteins share similarities with the ORC proteins of . We dissect the domain organization of ORC (trans-acting factors) subunits that seem to associate with DNA replication origins in We present a model of the 3D structure of CaORC4 to gain further insights of this protein's function.