No description available.

Caused by the organism Mycobacterium tuberculosis (Mtu), the globally distributed disease tuberculosis was responsible for the deaths of 1.4 million people in 2011. Anthranilate phosphoribosyltransferase (AnPRT) is an enzyme that catalyses the second committed step of the tryptophan biosynthetic pathway within Mtu, and is a promising target for antibiotics. This research aimed to further understand the mechanics of the AnPRT active site, in order to provide useful information towards AnPRT drug design. AnPRT inhibition and alternate substrates were investigated as well as variant AnPRT proteins, the results of which aided in unravelling a complex active site mechanism and illuminating several decisive inhibition strategies.

Sequenced diatoms Thalassiosira pseudonana and Phaeodactylum tricornutum belong to the chromist algae harboring secondary plastids, which display distinct evolutionary history when compared to photosynthetic organelles from rhodophytes, green algae and plants. Via secondary endosymbiosis, heterotrophic eukaryotic ancestor of diatoms engulfed red alga, and in addition to the new organelle, it obtained fitness increasing peculiarities in the chimerical cell metabolism and lifestyle. We examined phylogeny and in silico localization of the nuclear-encoded but plastid located enzymes of tryptophan biosynthesis. We suggest that the diatom tryptophan pathway represents an extreme in the trend of plastid (cyanobacterial) enzymes to be replaced by eukaryotic isoforms. In addition, the gene napped during the endosymbiotic gene transfer from the diatom plastid genome to the diatom nucleus (psb28) was described.