title: Conservation of structure and function of DNA replication protein A in the trypanosomatid Crithidia fasciculata.
abstract: Human replication protein A (RP-A) is a three-subunit protein that is required for simian virus 40 (SV40) replication in vitro. The trypanosome homologue of RP-A has been purified from Crithidia fasciculata. It is a 1:1:1 complex of three polypeptides of 51, 28, and 14 kDa, binds single-stranded DNA via the large subunit, and is localized within the nucleus. C. fasciculata RP-A substitutes for human RP-A in the large tumor antigen-dependent unwinding of the SV40 origin of replication and stimulates both DNA synthesis and DNA priming by human DNA polymerase alpha/primase, but it does not support efficient SV40 DNA replication in vitro. This extraordinary conservation of structure and function between human and trypanosome RP-A suggests that the mechanism of DNA replication, at both the initiation and the elongation level, is conserved in organisms that diverged from the main eukaryotic lineage very early in evolution.
authors.affiliation: Molecular Biology Institute, University of California, Los Angeles 90024.
authors.forename: G W
authors.initials: GW
authors.lastname: Brown
authors.forename: T E
authors.initials: TE
authors.lastname: Melendy
authors.forename: D S
authors.initials: DS
authors.lastname: Ray
mesh_terms: D000818:Animals; D002846:Chromatography, Affinity; D016831:Crithidia fasciculata / Q000235:genetics* / Q000378:metabolism; D004257:DNA Polymerase II / Q000378:metabolism; D004261:DNA Replication; D004268:DNA-Binding Proteins / Q000302:isolation & purification / Q000378:metabolism*; D004259:DNA-Directed DNA Polymerase / Q000378:metabolism; D006801:Humans; D046911:Macromolecular Substances; D051716:Replication Protein A; D013539:Simian virus 40 / Q000235:genetics; D013698:Templates, Genetic
chemical_list: D004268:DNA-Binding Proteins; D046911:Macromolecular Substances; C497167:RPA1 protein, human; D051716:Replication Protein A; D004257:DNA Polymerase II; D004259:DNA-Directed DNA Polymerase