Expression of ribonucleotide reductase small subunits PfR2 and PfR4. An asynchronous malarial parasite culture was immunostained with both anti-PfR2 and anti-PfR4 antibodies. Rabbit anti-PfR2 was detected with goat cy2 anti-rabbit conjugate (green). Mouse anti-PfR4 was detected with goat cy3 anti-mouse conjugate (red). The white arrows indicate sites of colocalization. Images were deconvolved using the Deltavision image restoration package. I, ring; II, trophozoite; and III, schizont. DNA was stained using DAPI. PfR2 and PfR4 showed distinct foci of cytoplasmic localization in all stages of intraerythrocytic maturation although some colocalization of both proteins can be seen, as evident from yellow merged spots.Bracchi-Ricard V, Moe D, Chakrabarti D. Two Plasmodium falciparum ribonucleotide reductase small subunits, PfR2 and PfR4, interact with each other and are components of the in vivo enzyme complex. J Mol Biol. 2005 347:749-58. Copyright Elsevier 2009.