title: Investigating the Roles of the C-Terminal Domain of Plasmodium falciparum GyrA.
abstract: Malaria remains as one of the most deadly diseases in developing countries. The Plasmodium causative agents of human malaria such as Plasmodium falciparum possess an organelle, the apicoplast, which is the result of secondary endosymbiosis and retains its own circular DNA. A type II topoisomerase, DNA gyrase, is present in the apicoplast. In prokaryotes this enzyme is a proven, effective target for antibacterial agents, and its discovery in P. falciparum opens up the prospect of exploiting it as a drug target. Basic characterisation of P. falciparum gyrase is important because there are significant sequence differences between it and the prokaryotic enzyme. However, it has proved difficult to obtain soluble protein. Here we have predicted a new domain boundary in P. falciparum GyrA that corresponds to the C-terminal domain of prokaryotic GyrA and successfully purified it in a soluble form. Biochemical analyses revealed many similarities between the C-terminal domains of GyrA from E. coli and P. falciparum, suggesting that despite its considerably larger size, the malarial protein carries out a similar DNA wrapping function. Removal of a unique Asn-rich region in the P. falciparum protein did not result in a significant change, suggesting it is dispensable for DNA wrapping.
authors.affiliation: Heddle Initiative Research Unit, RIKEN, 2-1 Hirosawa, Wako-shi, Saitama, 351-0198, Japan.
authors.forename: Soshichiro
authors.initials: S
authors.lastname: Nagano
authors.affiliation: RIKEN Structural Biology Laboratory, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, 230-0045, Japan.
authors.forename: Eiko
authors.initials: E
authors.lastname: Seki
authors.affiliation: Heddle Initiative Research Unit, RIKEN, 2-1 Hirosawa, Wako-shi, Saitama, 351-0198, Japan.
authors.forename: Ting-Yu
authors.initials: TY
authors.lastname: Lin
authors.affiliation: Division of Structural and Synthetic Biology, RIKEN Center for Life Science Technologies, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, 230-0045, Japan.
authors.forename: Mikako
authors.initials: M
authors.lastname: Shirouzu
authors.affiliation: RIKEN Structural Biology Laboratory, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, 230-0045, Japan.
authors.forename: Shigeyuki
authors.initials: S
authors.lastname: Yokoyama
authors.affiliation: Heddle Initiative Research Unit, RIKEN, 2-1 Hirosawa, Wako-shi, Saitama, 351-0198, Japan.
authors.forename: Jonathan G
authors.initials: JG
authors.lastname: Heddle
mesh_terms: D000595:Amino Acid Sequence; D027081:DNA Gyrase / Q000737:chemistry* / Q000378:metabolism; D006801:Humans; D016778:Malaria, Falciparum / Q000469:parasitology*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010963:Plasmodium falciparum / Q000737:chemistry* / Q000378:metabolism; D017434:Protein Structure, Tertiary; D015800:Protozoan Proteins / Q000737:chemistry* / Q000378:metabolism; D016415:Sequence Alignment
chemical_list: D015800:Protozoan Proteins; D027081:DNA Gyrase